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Showing content with the highest reputation since 04/06/12 in Blog Entries

  1. 17 points
    Since first posting details of my new set up on the Blogstronomy blog I've been literally inundated by an e mail from a Mrs Trellis of North Wales. Mrs Trellis writes "Dear so-called Top Gear. When are we going to get that lovely Ginger person back on Gardeners' Question Time? P.S. Show us some pictures of your new mount, scope and camera." Who am I to disappoint my fan base?
  2. 13 points
    It's a question that comes up regularly, but what is the difference between a Barlow and a telecentric amplifier (TA), otherwise known as a Powermate, ES Focal Extender. Meade Telextender, Bresser SA Barlow, etc? A telecentric amplifier does give a 2x magnification, just like a Barlow but that's where the similarity ends. A Barlow is a negative doublet (Smyth lens) that causes the exiting light rays to diverge and hence deliver the image amplification. If you move the EP further from the Barlow the magnification increases, whilst taking the Barlow nose-piece off and screwing it onto the EP will [generally] give 1.6x magnification, assuming we're talking a 2x Barlow. In the FE/Powermate/TE/SA Barlow (the latter isn't a Barlow, which is a confusion) the negative doublet is followed by a positive doublet that turns the exiting rays back to parallel - ie, telecentric. Because the rays are parallel, the distance between the EP and the amplifier elements is [broadly] irrelevant as the image amplification was done internally, between the TA lens elements. In practice, this still means that the effective focal ratio of the scope is doubled - It's a common misconception that the EP focal length is halved - but unlike a Barlow, the eye relief of the EP in use is unaffected. In other words, you insert an ES FE in the scope and the EP behaves exactly as it did before and the scope has effectively doubled in focal length. The down side is that double the number of lens elements costs more, but whereas a Barlow (which has other uses because of what it does) tends to feel like a second-best-to-an-additional EP, the ES FE simply feels like you have an extra EP. In visual terms, it's a less intrusive and more transparent solution and a more transparent device. So the Barlow is second best? Well no, not all of the time. For the reason why, you only really have to look at Televue Naglers and the clones thereof. They weren't the first (contrary to popular forum lore, but they're certainly the most successful) to use the idea, but what Unc Al realized was that whilst it was easy(ish) to create a wide field EP, the difficulty was in creating them at shorter focal lengths with an eye relief usable by humans AND with a well corrected field of view, especially in fast scopes like large Newts. Essentially, what he did was create longer focal length wide field EPs and then fit them with a Smyth (Barlow) element in the nose. Thus, you got an EP that acted as a shorter effective focal length, but had greater eye relief than it would have without the Smyth element. Very cool. In fact, this is the source of the reason why Naglers (and there derivatives) are renowned as well corrected in fast scopes. The Smyth element does increase eye relief, but as per a Barlow, it effectively increases the focal length and therefore focal ratio of the scope. As we know, a slower scope is less prone to aberrations, but in this case, it's the EP that is effectively delivering it. Your Nagler is better corrected, because it effects a better correct scope. So, this is also what your Barlow can do. A 20mm EP in a Barlow (and TA) will give a better corrected view than a 10mm EP, all other things being equal. This is handy, especially if you like your Orthos and Plossls which tend to have ever shorter eye relief with decreasing focal length. A Barlow can be partnered with a longer FL EP to give an effective shorter FL EP, without the need to glue your eyeball to the EP it emulates. Whereas a TA uses up it's focal length in the focal path, a Barlow does the opposite and pushes the focal point outward - It adds optical path length. How is this handy? Well if you have a binoviewer that uses up 110mm+ of focal path, the scope (refractors in particular) may not have enough space available to rack the focuser inward to compensate. A Barlow, or at lest the doublet element from the nose of it, screwed into the Binoviewer is enough to push the focal point outward and get you that focus point back. That's just one example. The important point is that whilst a TA is, as long as it has room to work, a generally superior device, there are times when a Barlow has qualities all of it's own. A good example of both will be a one off purchase and both will deserve space in your EP case. Buy right first time and you may find they remain a constant, whilst your prized EPs come and go..... Russell
  3. 12 points
    My new EQ8 mount is now back from my mate Chris. Chris made a 15cm high pier extension to raise the whole kit and caboodle so that the observatory walls don't get in the way so much. Because the whole mount + cameras/filter wheel/focal reducer + counterweights weighs in at an estimated 82 kg, the pier extension is made from a solid block of 19cm diameter alumunium! With this concentration of mass, gravitational lensing will now swamp the punny effects of 9.25" mirror on the C9.25". One the subject of counterweights, Chris got hold of a Celestron CGEM 7.7kg counterweight and bored out the central hole to 1.25"so that I can use it as a third counterweight on the EQ8. This allows me to push the two original 10 kg weights far higher up the counterweight bar.
  4. 11 points
    Following an inheritance, I've taken the decision to carry out a major upgrade of the set up in my observatory. Gone is my venerable Meade 8" LX200 and in has come a Skywatcher EQ8 mount carrying a 2nd hand C9.25 and my 80ED and my 66mm ED simultaneously. This is all held together using around 40,000 tonnes of ADM Losmandy dovetails and clamps. Added to this is an Atik 460EX Mono CCD camera + a ZWO 8 position filter wheel with a full set of Baader RGB and narrowband filters and I am one very happy bunny. Now comes the hard work. It's going take a LONG time and a lot of work to set this all up properly and to learn how to use it all. I've decided that I'm going to try really hard to spend at least 90% of observing/imaging time in 2017 just setting it up and getting to know how to use all this new stuff. I already seem to have spent an equivalent to the combined national debts of Greece and Spain on adaptors, rotating adaptors and spacers. Because I really haven't got enough to do already, I'm also taking the opportunity to switch over from PHD to PHD2, to build an Arduino-based focus controller, to learn how to use Sequence Generator Pro and to install a new 12v power supply in the observatory. Happy Days
  5. 11 points
    I threw an opinion into the mix in the beginners forum the other night and decided I should expand on my reasoning here. Even somewhere as benign as SGL, you still have to remember this IS the internet. That means opinions repeated enough by people with large post counts, gain credence as fact among the rest of the forum. It does not hurt to challenge that, if only to get people thinking, as long as you do it in a reasoned way. So..... What got me thinking was the humble 8" Dob. For instance, I've noticed that the most recommended scope for a beginner is an 8" Dob; 10" if there's a sniff of the OP having a bit more to spend. The thing is, a rake of this recommendation appears straight off the bat, without further quizzing of the OP, but for most newbies, I think it is wrong. True, a great many people started there and went on to bigger (some might say better) things, but a lot do not. You don't have to be Poirot to notice it's also the most sold scope on Ebay, along with the EPs it came with; reasons (excuses) of needing the space, etc, being given. The ratio of 8" Dobs for sale on Ebay is greater than on here. A lot of people don't stick with it long enough to achieve the fifty posts required for access to the classifieds. Why? Because if you don't know your way around the skies, you'll find it really hard to find stuff and you'll break your back grovelling around doing so. It is also a scope that will likely be way off the mark in collimation out of the box and be harsh on the rather basic EPs* it came with. When I started, my Explorer 200p only showed half the primary when looking down the focuser. They really can arrive that far out of whack and dealers these days are driven by price, so they are extremely unlikely to have seen more than the outside of the box you've been shipped. Few would actually check the scope and if they did, most people would whine they're too expensive. Service costs. So, if you do find something on your first light with your new scope and then pop in the 10mm MA it came with, it will look rubbish. De-collimate your scope with a half decent EP and have a crack at Jupiter. It's not impressive and that's as easy as it gets. For a n00b, it's confusion time. In other words, it's not the most intuitive scope, it has a built in steep learning curve just to get it to work and requires immediate upgrades just to get near what this, admittedly capable scope in the right hands, can deliver. The 8" Dob is best suited to someone who has at least used binos, or a friend's scope. That way, they'll have advice on hand. So my contention is that, in this push button, battery driven age, the ideal beginners scope is a 127mm AZ GOTO Mak. I can hear the hackles rising, so let me justify this. I'm not interested in the cries of 'It needs to be level, it needs to be pointed North!'. That involves a bubble level and the one star everybody knows. People who get the date format wrong should RTFM! Anyway, if this is tricky, how are they going to get along with a Planisphere? No, the learning curve is minimal and when the crisp little optics and it's long FL, which is easy on cheap EPs hits a target, it's going to be a sharp view. If it doesn't hit the target first time, the erstwhile n00b will slew around a bit and unless they're complete attention deficient, will hit the target. This is my point. Getting the first few targets a newcomer sees to be clear, is the hook that keeps them engaged. Jupiter will look good in a Mak. Saturn at any size when sharp is unforgettable. The moon will look amazing and M42, M57, globs, etc, will be good enough to show people there's a universe out there they hadn't even considered. I know an 8" Dob will do these subjects better, but it's not exactly Wow! territory. There are plenty of atmospheric UK nights and particularly from suburban locations, where a 5" Mak might actually do these subjects better. Now I know that hardly anybody reading this will still have their first scope, but if one of these had been, it would still be a great little grab 'n' go, plus a handy mount for an 80mm ED/Apo for the same purpose, plus white light solar, etc, etc. Nobody who starts in the hobby with an 8" Dob stays there. In the long run, rationally, the humble 5" Mak GOTO is a very handy little weapon on a number of levels and one that has uses further down the line. Russell * One of the scopes I bought at a time when my collimation learning curve had long since flattened off, came with the usual 10 & 25mm MAs. For a laugh, I thought I'd give them a go. You know what? In a 300mm F4.9 Dob, they weren't that bad. The deficiency I recalled, was in fact, mostly mine in terms of collimation - It was far easier to blame the EPs and post yet another 'What EP for a n00b' thread....
  6. 11 points
    This article considers the financial perils of astro-photography, because while a hobby like Astronomy can at times leave you financially challenged, nothing is quite so fiscally ruinous as deciding it would be a jolly good idea to fasten a camera to your telescope. There are many reasons you might consider taking up astrophotography. Perhaps, as your eyesight slowly declines from the hawk like clarity of youth to Mr Magoo myopia in your advancing years, astro-imaging appeals as a way of extending your hobby into pensionerhood. Or it might be that you’re fed up of seeing things like the Andromeda galaxy and the Orion Nebula as greyish blobs and smudges and instead yearn to produce the same beautifully detailed, colourful pictures you see in the astronomy press. There is absolutely no doubt the images amateur astronomers produce are incredible. At first glance you’d think they had come from the Hubble space telescope rather than a man in a shed somewhere in Liverpool. They are impressive not least for the fact they may well have used a telescope much like the one you already own, so the equipment must surely be quite modest in its expense. Interesting word though ‘modest’. It makes it sound like it could mean fairly cheap. Not bargain basement certainly, but definitely somewhere around ‘affordable’. When it comes to the cost of astrophotography though ‘modest’ means cheap in much the same way a telescope like Hubble is ‘affordable’. It could be reasonably argued that the theory of black holes was dreamt up by someone bitten by the astrophotography bug to try and explain where all their money had disappeared to. Like all addictions it will start innocently enough. This one will start with a web cam. You might even buy a cheap one from Asda and modify it yourself for astronomy purposes saving a bit of money. This is your last chance to kick the habit before it really gets its hooks into you. Only if you fail to correctly modify that web cam and end up ‘fixing it’ with a hammer in a haze of red mist and frustration will you escape its clutches. Should you succeed and manage to get the thing working you will be lost. The web cam will last you a little while but once you've captured a picture of Jupiter that you’re really happy with you’ll begin to feel the itch of deep sky objects and to scratch that itch you’re going to need a second mortgage. Where to begin? Firstly you’re going to need a camera. As you are not quite fully in the grip of your astrophotography habit yet you’ll make the concession of buying a DSLR Camera. You’ll justify the expense by telling yourself you will be able to use it as a ‘normal’ camera and take holiday photo’s and pictures of robins on your bird table in winter. And you might very well start out that way but then you’ll read an article on disabling the infra red filter and that will be that for the sandcastles and robins. If you have a shed you’ll begin to think of it as your observatory and draw up plans to modify it to have a roll off roof. But to fit the rollers you’ll have to take the roof off and to fit the pier for the expensive new mount you’re going to buy, you’ll have to take the floor up. This will cause your shed to fall down so you’ll end up rebuilding it. However the new shed/observatory will be twice the size of the old one once you've added the essential warm room and kitchen area. So, you've built a new shed and installed a pier, bought the camera, and at least a NEQ6 Pro mount,. But it’s only just begun. You’ll need a guider scope, off axis guider, laptop, full set of colour filters with wheel, narrowband filters, light pollution filters, the list goes on. Then you’ll look at your telescope and decide you need a different one, which when it arrives you’ll modify, changing the focuser and adding a home-made cooling solution you saw on astronomy shed. If you are not an eccentric millionaire you’re now at the point where you need Bob Geldof to organise a charity concert to pay off your debts. So before you start your next round of upgrades you’ll do some imaging which will involve taking up permanent residence in your shed/observatory. There are two main reasons for this. First it’s where you now spend all of your waking hours fiddling with your equipment, taking many millions of exposures and practicing the dark arts of image processing. The second reason you’ll spend all of your time there is because your house has been repossessed and this is now your home. Finally, after the flats and darks have been taken, the data crunched and the final tweaking of levels in Photoshop has brought out the dust lanes in Andromeda just so, you’ll post your masterpiece online. The accolades from your peers will be justifiably fulsome in their praise and all the hard work and sacrifice will have been worth it. That is until some nit picking, pedant will point out a minor aberration in an unimportant part of your image. Once the twitching has subsided and your blood pressure has returned to a level no longer considered ‘dangerously high’ you’ll have no option but to reach for your credit card and buy some more kit. Let’s see now, £6000 for a proper mount, hmm, maybe I can sell a kidney.
  7. 10 points
    Three Weeks in the Wilderness Between the 9th to the 22nd of August, I was fortunate to spend almost three weeks camping with my girlfriend in the natural park of Causses du Quercy, France. It is a beautiful area of hidden caves, prehistoric artwork, gorgeous villages, mellow rivers, cool breezes and summer sun, delicious wine, cheese and paté and some of the most precious skies in Europe. I was fortunate enough to take along my 10" Moonshane and head out with my girlfriend to an area known as The Black Triangle. Here, at night, the only light you see is that from the stars and from the Moon. Nature has given us two joys to accompany us through life: the playfulness and cheer of day and the solemn and silent night. In the first of these geniuses we visited the area; strolled rustic villages, dined on five course meals, had siestas by slow rivers and took trips into the underworld, a torch lit boat ride along underground rivers filled with ancient stalactites and stalacmites, another to visit prehistoric artwork and witness mankind's lasting steps into art and creation. At night, armed with pencils, blending stub and sketchbook I headed out into the darkness, into that night sky bent gently over my head revealing to me its infinity of tangled curls and wonder. Each night was a different voyage, some predominatly amongst doubles, others with NGCs, galaxies, nebulae and clusters. Many hours were spent just sitting back, ignoring the telescope and drinking in the slendour. It is impossible to include everything, sketching is an exhausting and concentrated effort and at best I could manage an average of about two a night. Although these sketches cannot do justice to nature's sublimity, I hope they give a hint of what was witnessed. Here, then, I include the sketches I made of just some of Messier objects viewed and a particular NGC. M 2 M 8 M 11 M 13 M 15 M 16 M 17 M 20 M 21 M 22 M 23 M 24 M 26 M 27 M 28 M 31, M 32, M 110 M 33 M 34 M 45 M 52 M 57 M 72 M 73 M 74 M 75 M 76 M 81, M 82 M 92 M 101 NGC 6960
  8. 9 points
    Chris’s Backyard Astronomy. January 2017. A view beyond Earth’s lifetime Happy New Year to everyone. This month I am going to concentrate upon one topic only; something that came to my attention at New Year. The item in question is described as a QUASAR and makes a year in my life appear extremely insignificant. Eyewitness report: “Almost Older Than Time. Would we be able to see it? On Monday the 2nd of January we gathered in Chris's back garden observatory to spot a tiny pinprick of light that had been travelling 8 billion years, yes that's right 8 BILLION YEARS to reach us! Chris had done his homework, mapped out its position and identified a few pointer stars to help us in our search. The bright moon and lovely Venus stayed handily behind the house so a reasonably dark, clear sky helped us in our search. Our luck was in, the pointer stars in the shape of a triangle were in the (telescope) field of view and using averted vision I spotted our faint target, impossible to grasp the enormous distance through space and time the photons from this QUASAR had travelled. Once spotted it was easier to see it again as we all took turns to look at this black hole in action; a successful night, thanks Chris.” Susan Feist Quasi Stellar Radio Sources (QUASAR) The name was adopted originally because such objects were first observed by ‘seeing’ their radio waves and so they were assumed to be stars. Remember, telescopes are not just available to see things with your own eyes but some are capable of detecting lots of other forms of energy. The Jodrell Bank telescope near Manchester for example was once the greatest radio telescopes in the world. Jodrell Bank Radio Telescope: Image credit mattbuck Up until the 1960s a multitude of radio wave sources out in the sky were listed and catalogued. Critical to identifying these objects were to accurately log their precise position and then try and get identification too with a powerful visual telescope. This proved possible in some cases and as a bonus it was possible to catch the light and determine the spectrum of the object (see my previous column). Once you have the spectrum you can find out a lot of important information. However, visual recognition and thus scientific interpretation of some of these QUASARs eluded astronomers. 3C 48 I quote a lot of numbers and acronyms but really it’s not that complicated. QUASAR 3C 48 was the 48th entry in the 3rd Cambridge catalogue of radio sources. In 1960, using a huge 200 inch telescope, astronomers Sandage, Matthews and Bolton finally pinned this particular radio source to a 16th Magnitude star. Mount Palomar 200-inch telescope. Image credit: Coneslayer at English Wikipedia A refresher on magnitude Remember, the magnitude scale works counter-intuitively in reverse. Each step is a change of about 2.5 times in brightness. For example, to us the full Moon looks about 60,000 times brighter than the bright star Vega. On the other extreme QUASAR 3C 48 is about 10,000 times DIMMER than the dimmest star we can see with the naked eye! Object Magnitude Brightness we see on Earth The Sun - 26 Midday Sun Full Moon - 12 Moonlit sky Venus (now) - 4 Bright evening ‘star’ (now) Jupiter - 2 Yellowish star like Vega (bright star) 0 5th brightest star in the sky Yildun + 4.5 Star just visible with your eye Neptune + 8 Farthest planet appearing reasonably bright in a 10 inch ‘scope 3C 48 QUASAR + 16 At the limit of a very large amateur ‘scope Capturing the light from the QUASAR to enable a spectrum to be examined was some feat in those days but they did so. Sandage though was quoted describing the spectrum as “exceedingly weird”. What followed was a 3-year period of doubt and false reasoning because the spectrum just could not be interpreted within the range of known objects. In 1963 two other scientists, Schmidt and Greenstein, re-examined the spectrum of 3C 48 from 1960. Schmidt had previously examined a spectrum of a similar object (3C 273) and was thus experienced in these matters. What he immediately concluded was not weird but that object 3C 48 showed a “redshift of 0.37”. So, now we need a recap on redshift. Hearing an ambulance Recall the last time you stood by as the ambulance sped towards you and then away from you. We are all familiar with characteristic change in pitch of the siren. As it approaches you the pitch gets higher then as it leaves you the pitch gets lower. The lowering of the pitch as the sound source moves away from us is due to a ‘stretching’ of the wavelength caused by the speed of the ambulance relative to us. This is the Doppler effect and applies to all types of radiation including light. Normal spectrum above and red-shifted spectrum below. The tell tale absorption lines are moved to the right. Credit: Georg Wiora (Dr. Schorsch) via Wikimedia Commons So Schmidt was saying that the spectrum of QUASAR 3C 48 told us that it was (and still is) moving away at truly phenomenal speed! As we have discussed before, the painstaking work of Edwin Hubble in the 1920s enabled a connection to be made between the speed that an object is receding and its distance. On doing the maths 3C 48 was located at 4 BILLION LIGHT YEARS distant. Ancient photons hit Bishop Monkton This dramatic distance estimation created disbelief in the astronomical community. Knowing how bright the object looks to us (Magnitude +16) and also knowing its distance, enables us to quite easily determine its true brightness close up and thus its power. The calculation for most QUASARs shows they have the luminosity of 10 Trillion (10,000,000,000,000) Suns, easily one of the most energetic objects in the Universe! As you may imagine this stimulated a decade long argument as to whether the observations were true or were these QUASARS just objects in our own galaxy that demonstrated weird physics? In more recent times, advancements in technology have enabled astronomers to study ‘normal’ galaxies in the region of these QUASARS and confirm that indeed they are very distant objects. On the 2nd January 2017 a group of villagers and friends congregated in my humble shed known as the Observatory and eventually, one by one caught a glimpse of light that has taken 8 BILLION years to get here. I stumbled across a reference to QUASAR 4C 11.69 also known as CTA 102. It is in the constellation of Pegasus looking west from the village at the moment. The old 9 inch SCT telescope used to spot the QUASAR This particular QUASAR was originally falsely classed as a magnitude +17 variable star. Variable stars are quite common but are usually quite regular in their variability. Not this one! Recently its magnitude has changed from +17 to nearly +11, which is an increase in brightness of 250 times. Think about this for a moment. This is an object that is TWICE the age of the Earth, more than half the age of the entire Universe as we know it and visible in my 9 inch telescope. Surely this is the most powerful and most distant visible object any of us will witness. Its brightness currently varies quite substantially on a daily basis so what is it? CTA 102 was discovered in the early 1960s from its varying radio source but was laughingly thought to be signals from an extra terrestrial intelligence and American folk rock band The Byrds wrote a song about it in 1967 called ‘Younger Than Yesterday’. It is in fact a giant black hole at the centre of a distant elliptical galaxy and its brightness is determined by what it is currently consuming. So the recent huge increase in brightness is a burp of cosmic proportions quite possibly as it gulps in stars or even other galaxies. I write this in the present tense but it is highly likely this object ‘died’ eons ago and no longer exists. A QUASAR; a disk of stellar material feeding a huge black hole and artist’s depiction of data via NASA’s Spitzer and Chandra telescopes. Credit: Nasa JPL The village group found it a challenge to observe but with careful attention to excluding all other light sources and using averted vision I believe all present witnessed the 8 BILLION year old photons. Retiring to the kitchen to consume a well earned cuppa, some of us had another peek about an hour later and it had significantly increased in brightness in that time so obviously it had done similar to us. What next? A few days later, from the observatory I captured a star field image to show the QUASAR CTA 102 here in the centre of frame against known reference stars. This is a stack of 20 x 30 second exposures. QUASAR CTA 102 approximately Magnitude 12. 8th January 2017; Chris Higgins CTA 102 is now going out of reach. If it is still belching at the same rate in the Autumn we should check back then to see if it has satisfied its hunger. Feel free to join me. Follow my Twitter feed for regular updates on this and new topics from the backyard observatory. Twitter: @owmuchonomy Astrophotos: https://www.flickr.com/photos/blue5hift/sets
  9. 9 points
    This in the first in an undoubtedly infrequent series of ramblings from Michael Morris, unsuccessful amateur astronomer and prog rock fan. I thought I start off with a success story of sorts (lap it up now as there won't be many of these!). A couple of years ago my youngest daughter upgraded her old Windows Vista (spit) laptop to a Macbook. The old laptop sat around nontionently being a laptop for a few months before, in a desparate attempt to stop having to run Windows Vista, decided to start overheating and turning off after five minutes of running. And for three years it sat at on shelf in the study doing a really good impersonation of a somewhat odd-shaped paperweight. Fast forward to a couple of weeks ago when I decided I could do with a second computer in the observatory for running the all sky camera. I decided that, in my own mind being a minor deity, I would attempt try a Lazarus-like reanimation of the Vista paperweight. Remarkably, I managed to diagnose the problem as a non-functioning fan. After toying with various ideas,including strapping a fan on the outside or throwing it under a train, I decided to go the whole hog and replace the fan. Looking on Youtube I discovered to do this I would have to dismantle the entire laptop! In a fit of uncharacteristic electronic confidence I spent last night dismantling the laptop and fitting a new cooling fan. Putting it back together didn't go entirely to plan as I have four very small screws left over! Then came the moment of truth ... ... it only went and worked!!!!!!!!!!!!!!! I've tested every function and socket and all seems okay. So now I have a working second laptop with all my astro programs loaded. Success? Well, NO. I made the mistake of sharing my surprise success with the gorgeous Ilona, my wife of 30 years and mother to my three children, Being the kind, thoughtful and generous sort that she is, her reaction to my good news was "Well done, that's great. Eliza (the older of my two daughters) needs a new laptop as her old one has died. She's a bit broke at the moment so you could give her the one you've just fixed." Drats, foiled again.
  10. 9 points
    The Eskimo Nebula - A View from the Arid Lands By Way of Introduction In a manner of speaking, we are born out of the earth, walk on it for a while and finally become part of it when we die and so too with a star. It is born out of the cosmos, wanders it for a while and finally becomes a part of it when it dies. In this way, both a star's existence, like a human life, is a rite of death, a being-towards a something else; a transformation. The physical recycling of life serves as a reminder of our own ultimate fate and likewise that of the Sun; for the star that was once the Eskimo Nebula is a good illustration of what the Sun’s own passing away will be like as it ejects its matter into space, forming giant gas and dust clouds which may condense with other interstellar material into planets and stars, comets and meteorites and organic life. The Eskimo Nebula or NGC 2392 The Eskimo Nebula or NGC 2392 was a sun much like our own, a typical main sequence star chugging along in a steady state of nuclear fusion, transforming 700 million tons of hydrogen into helium every second for billions of years. Then about 10,000 years ago - as the ice-age was coming to an end - the hydrogen supply in the star’s core ran out. Nuclear fusion ground to a halt and through the force of gravity, the helium core collapsed creating temperatures high enough to trigger the fusion of helium into carbon and oxygen. Far from the burning core, on the outer hydrogen layers, the star was expanding into a red giant, a colossal stellar object with a diameter of at least 2 AU. Once the helium fusion ended, the core collapsed again, but now there was not enough energy to spark further nuclear reactions or to counter the force of gravity and so the star collapsed until it was about the size of Earth and became a white dwarf. The Eskimo’s white dwarf is a relatively small object in terms of volume but it packs a lot of mass. It is probably about the size of Earth but with a mass equal to that of the Sun. Surrounding this stellar remnant is a shell composed of expanding helium and hydrogen gases whose electrons are excited by ultraviolet radiation emitting from the white dwarf in the form of stellar winds. The excited gas is visible as a planetary nebula, detected in a small telescope as a bright, ghostly cloud whilst with deep exposure you can witness one of the most captivating and intrinsically beautiful objects found in the natural world. Not only is the Eskimo Nebula aesthetically gorgeous but as with all things which must come to pass and die, it too contains the building blocks of life. Spectroscopy has detected four primary elements within it, namely, hydrogen (green), helium (violet), nitrogen (red), and oxygen (blue). Indeed, the nebula’s name derives from these gases which light up as a ‘hood’ surrounding a ‘face’ made up of two elliptical lobes. No doubt, the snub that is the nose is the small central star. The Eskimo Nebula is estimated to be anything from 2,870 to 5,000 light years from Earth, has a diameter of about half a light year and the gas we see probably left the small central white dwarf some 1,500 years ago. If this is so, NGC 2392 is one of the youngest planetary nebula known. A Sketch & Observation The planteary nebula lies in the constellation of Gemini and even with the small 4” refractor, it was clearly visible and held up well to magnification. As can be seen from the sketch, there was a brighter central region surrounded by a fainter halo of nebulosity and although the inner circle hinted at more detail, due to average seeing conditions and probably being at the refractor’s Dawes limit, the tiny white dwarf at approximately magnitude 10.5 was not seen. However, this was not important. That bitter evening this sketch was made the Eskimo Nebula shone forth as a comforting metaphor. The original sun - which had been so much like our own - was now long gone but it did not sleep, it had not died. It was just something else. Equipment used for the observation was a Tal 100rs, an 18mm X-Cel LX mounted on an AZ 4. The sketch was drawn the 12th of November, a cold night using a 4B, 2B and B pencil for the stars and a blending stub for the nebula.
  11. 8 points
    Recently had some bad personal news so did what I usually do in these circumstances.....I bought a new scope To be precise a Synscan 127mm Maksutov from Rother Valley Optics (no planned advert but have to say great service) At last clear skies tonight so set up my new scope, used 2 star alignment, Regulas and Sirius as my garden is only any good towards the south (street lights everywhere else), really simple, five minutes and up and running. Quick tour using handset for messiers and whipped through M46, M47, M48 and M50, followed by the Christmas tree cluster and the beehive With 25mm and 15mm eyepieces I have to say the Mak was a revelation, great views and a fun evening Looking forward to some great nights with this little treasure
  12. 8 points
    Hi all Been a while since my last entry, so thought it about time to log another! Things are getting a lot busier at work. My area has changed, and I have now taken on Norfolk, along with Bristol and South Wales. I am a Regional Systems Manager for Greene King Pub Co. and look after all the sites IT and till equipment. So, more sites means more meetings and more miles, but I love it - getting out and about, and seeing areas of the country I haven't been too before. The other day I had to drive from Shrewsbury to Sheffield, and the SatNav took me over the Moors near Manchester, and the High Peaks near Buxton. It was a lovely drive!! As a result of the above, my leisure time has taken a bit of a hit, but I have still managed to get out with my Telescope on quite a few occasions, albeit from the back garden. When the weather has cooperated anyway! I will do a more detailed write up later, but I have made good in roads on my Lunar 100 challenge, and also made good progress in re-learning the sky. All being well, I will be heading up to the area around Ashbourne / Ilam in a few weeks. I have a friend living out in the sticks, and he has graciously let me use his back garden. Its proper dark there - compare to my garden anyway, so that’s something to look forward too. I have also taken my first, probably ill-advised step, into AP!!!!! I went out last night and took some pics of the full moon. I used my 25mm eyepiece, and hand held my iPhone up to it. I wasn't expecting anything amazing, but was fairly pleased with the results: Not completely in focus, but as I said, it was all hand held! Makes me think if I can mount the phone in some way, I could get some sharper shots. I have also found an old webcam - I have butchered it, and made some adaptions to allow it to attach to the focuser. I gave downloaded various software to hopefully allow me to get some video of the moon for stacking purposes. Not tried it yet, as I need to get a longer extension lead for the laptop. But I think it should work ok. I will do a full post on it once it has been for its first test drive!! Clear Skies!! Nige
  13. 8 points
    Since shortly before xmas I've been developing a piece of software to support electronically-assisted astronomy (EAA). Realistically it is still some months away from release, but the main design elements are getting close to being fixed so I think now is a good time to document what I'm doing in the hope that any comments or suggestions might be taken on board before the thing fossilises too much. The tool -- codenamed Jocular -- aims at promoting observation, but getting the most out of the limited number of photons we EAA-ers typically collect for each object we observe. The interface will be kept as simple as possible, but in spite of this I'm planning to implement a fair bit of AP-like functionality, adapted to the EAA use case where nearly all processes have to be handled semi- or fully-automatically. In a sense the tool was motivated by a desire to experiment with just what is possible to accomplish in near real-time and minimal user intervention. So there will be support for a full calibration scheme but operating silently where possible, as well as various luminance-chrominance manipulations, gradient removal and advanced stacking and stretching options. I'm attempting to operate by the principle of least commitment, which is especially important for EAAers, whereby it shouldn't be necessary to take decisions in advance that limit later options and potentially waste photons. For example, it will be possible to reject subs from any earlier point in the stack, or change the stacking mode, or choose a different key frame for star registration, or re-assign incorrect subs to the appropriate type or to a different object -- at any point during the observation of that object. Currently, live mode operates via a 'watched folder' approach in which an arbitrary capture program dumps .fits into that folder. These can be darks, bias frames, flats or lights, or short captures used for FAFing (focus-alignment-framing); a user-defined naming template enables the program to sort out the type of each sub. However, I am one small step away from complete integration with Nebulosity, which will enable capture control for any cameras/filterwheels supported by Nebulosity, but all done via a simple interface. The Nebulosity option will also allow scripted captures, again heavily simplified e.g. click RGB to have the program capture N subs of duration D from each of RGB, rinse-and-repeat (assuming the user has an electronic filter wheel). I hope to support INDI-based capture/control at some point and would like to track down some compatible open-source capture options as this is one area I really don't have the time or inclination to work on. It is possible to use the tool both live and offline in much the same way. The tool will provide easy access to previous observing sessions, enabling a user to revisit and re-process the data in a 'what if' fashion. It will support observation planning and logging as well as image annotation. The program is being written in Python. In principle it can be ported to all OSs, including iOS and Android, but I'm developing first and foremost for the Mac where there is a shortage of EAA tools. The software will be open source. Here's a shot of the current interface during a recent test session observing the polar ring galaxy NGC 660 in Pisces.
  14. 8 points
    Ok, so the photo isn't a classic but to me it's a masterpiece :-) ...the first time I have ever seen Jupiter through a telescope let alone been able to photograph it. Pretty awesome to be honest considering I've managed to take a photo of a planet over 550million km away and whilst I don't think it'll win any prizes it has made me a happy man!
  15. 8 points
    It's been a while since I posted anything here so to rectify that read on to discover why the moon is like Scarlett Johansson and along the way Galileo, Buzz Aldrin, ET and a drunken zombie all get a mention too. Any astronomer with any degree of experience will have a list of things they really want to see. Many, for example will have no doubt fantasised about seeing Betelgeuse going supernova perhaps while they happened to be looking at it. Or it might be watching a comet perform a death plunge into Jupiter and observing the resulting scars in its atmosphere, which would no doubt be an awesome sight to see. Maybe some people even secretly hope to discover an asteroid on a collision course with Earth that is big enough to send us the way of the dinosaurs. But when you first began your adventure in astronomy your list will be slightly more prosaic. For a lot of people their number one must see is Saturn in all its ringed glory. No matter how many times you see it, it is simply spectacular. Or perhaps it is Jupiter and its four largest moons that pretty much look the same today as they did when Galileo first observed them with his telescope four hundred years ago. And then of course there are old favourites like the Andromeda galaxy, the Orion nebula or the slightly disappointing Mars. For some it is simply going to a dark sky site and seeing more stars than you believed existed and being awed by the sight of the Milky way arching overhead. These are all worthy objects that appear in any astronomers top ten sights to see in the night sky. One thing a lot of people don’t have down as a priority though is the moon. This is surprising since it’s the most obvious thing people recognise in the night sky but also understandable for the very same reason. Everyone is so used to seeing it mooning at them all night and sometimes during the day that they feel they’ve seen it all before. Yes, people always marvel at the way it looks bigger when it’s closer to the horizon and everyone likes that bit in ET when Elliot and co. fly in front of a huge full moon, but give someone a telescope and it’s not usually the first thing they look at. There is some truth in thinking that the moon is so familiar that there is nothing new to see. Many features for example can be picked out with the naked eye and most people are aware that we only ever see one side of it so it is a bit samey from that point of view. But, and it is a big but, when you do finally swing your telescope around to the Moon you will stand in slack jawed amazement and say the only word your brain can push out of your mouth at such times which is ‘Wow!’. You might ask how is it possible to be so awed by something that appears so ordinary but the answer to that question can be most concisely summed up as “Magnificent desolation”. Those were the words of Buzz Aldrin when he hopped off the lunar lander and had a look around and when you put a high magnification eyepiece into your telescope and point it moonward you’ll know exactly what he meant. You will be quite simply astonished and wonder how you failed to realise what a beauty of an object it is. It is the astronomical equivalent of barely noticing the girl next door for several years and then one day bumping into her at the bus stop and realising she’s Scarlett Johansson. And in much the same way you will then spend a great deal of time late at night in your garden with some binoculars. The particularly brilliant thing about the moon though is the level of detail you can see. Let’s face it many objects that we spend time looking at can best be described as fuzzy and indistinct. Even the planets in the solar system reveal very little detail to the visual observer and when they do you are talking of features hundreds if not thousands of miles in size. The moon is different. Here we’re talking objects perhaps as small as a kilometre that can be resolved by even a modest telescope. Regardless of the power of your equipment though you will spend hours peering through your telescope discovering little gems of detail in the many craters and mountains you will see. You’ll crank up the magnification to ridiculous levels which you can get away with when the thing you’re looking at is so close and so bright. When the moon is full and with just the right eye piece you’ll be able to fill your field of view with the entire moon and it looks brilliant. The only down side to staring at the moon for the first time is that you probably won’t have the benefit of a moon filter and you will discover the brightness of la luna has left you temporarily blind in one eye. I’ve never tried looking at the moon through binoculars but presumably doing so leaves you stumbling around like a drunken zombie until the effect wears off. Luckily, if you’re the owner of a Newtonian reflector, particularly the Skywatcher variety there is a solution of sorts that comes free with your telescope. It could be described as the end cap, end cap. To explain, here's a picture of the end cap of my telescope, note the small end cap removed from the much larger one. Many people puzzle over the intended use of this little hole but one thing you can do is use it to cut down the glare when observing the moon. You simply leave the large end cap in place and remove the small one and voila light entering your telescope is reduced substantially and you can thus observe the moon without the usual temporary blindness. However the problem comes when you've finished your lunar observing and decide to have one more look at Jupiter before you pack up. ‘Hmm, that's funny’ you'll think. It’s very dark and really lacking detail and it looked brilliant earlier. You may swap out an eyepiece, check you've not got a filter on and in desperation you'll fiddle around with things that can't possibly affect your view. Bewildered you'll start to pack up your stuff and when you go to take the dew shield off the end of your telescope you'll notice the big end cap still in place with just the little hole open to the universe. Happily it will be dark enough to cover your embarrassment and you can pretend that you knew it was there all the time.
  16. 7 points
    Hello there!! Yeah, its been a while since my last blog post. Work and family life have been unbelievably busy these past months – added to that the summer nights being short, things on the astro front have taken a bit of a hiatus. However, the nights are slowly drawing in now, and following our recent holiday to Cornwall I am slowly getting more time to get out under the stars! A couple of weeks ago, we took a family holiday to Cornwall. We stayed on a working farm, on the edge of Bodmin Moor. I had done some homework, and the farm had Bortle 4 skies, compared to my 6 at home in Derby!! I was looking forward to seeing some proper skies! The first few days, while warm and sunny, moved to cloud in the evenings. However, I got my chance on the Wednesday evening – clear skies from horizon to horizon! I waited for the sky to become fully dark, and went out into the little garden we had the use of at about 10:30pm. I was lucky – the farm didn’t have any floodlighting, and the only light was a security lamp on the farmhouse. I was well hidden from it anyway in the garden. I wasn’t able to take my 150pl with me (too big!!), but took my Celestron 20x80’s along. After my eyes became adjusted, I was rewarded with one of the clearest and brightest skies I had seen since my days living in rural North Norfolk! The Milky way was a bright band across the sky, with Saturn nestled in it toward the horizon, and so many stars I had trouble making out the constellations! M31 was bright and clear, and Double Cluster was amazing. I spent a good half hour just sweeping my bins along the star clouds of the Milkyway. It was then I decided to go and get my camera, and try and my hand at some basic AP. I set up my tripod and Canon 400D, set the ISO to 1600 and opened the lens to f2.8, and pointed it at Casseopia with a 30 second exposure (couldn’t do any longer than that as I had forgotten my cable release!). The image came back and even on the LCD I could see I had captured a lot of detail! I took a few more, and the results are below. Did some basic editing in CS-5 – just tried to make the detail stand out a little more. Am quiet happy with them – only 30 sec exposures! The lack of LP was a real bonus!! This has ignited my desire to take the AP further. Nothing like getting an expensive mount (yet!), but I plan to get the dual enhanced motors for my EQ3-2 and attach my camera to that. Hopefully I can get at least a couple of minutes exposures at moderate focal length. I only have a 17-55mm lens, but is the f2.8 version. I have also looked into getting an adaptor so I can attach older FD lenses to the 400D. There are some real bargains on Ebay for 135mm / 200mm and 300mm FD lenses. I will do a separate review of the place we stayed – it really is perfect if you are looking for base to explore Cornwall and Devon ,and also want dark skies at night!! Thanks for reading, and hopefully, it won’t be 6 months before I post again!! Cheers
  17. 7 points
    Just got back from Iceland having enjoyed a few days sploshing about in the geothermal waters, looking at waterfalls and geysers and eating lots of cod. As you can imagine, we were very excited at the prospect of seeing the Aurora Borealis. Unsurprisingly, nights went by under a dense blanket of cloud. Then, on the morning of the last full day of our holiday, the sun came out and so did we. After a full 10 hours traipsing about a glacier and investigating basalt columns on a black beach we returned to our hotel in Reykjavik. Night fell - clunk! One by one all the light pollution came on all over the city - but what was that faint sepulchre glow advancing from the far North across the slate grey Arctic Ocean? Hurrah at the twelfth hour we got to see the Northern Lights. An excellent display it was too - lasting for about three hours. With the naked eye we could clearly distinguish green , magenta and blue light and we managed to take some photographs. Our astronomical cup overflowed. I have attached a rough and ready annimation which gives some impression from the early moments of the display.
  18. 6 points
    A belated Merry Christmas and a Happy New Year to everyone! I do hope everyone had a fantastic time over the holidays. Well, Santa has been very kind to me this year, and on Christmas morning I awoke to a huge box in the living room – it had been too big to wrap, and anyway I knew what I was getting lol!! So, I am now the proud owner of a Skywatcher Explorer 150PL. it was ordered from RVO at 4pm on Thursday afternoon, and arrived early on Saturday morning – great service!! I had um’d and ah’d for ages on what OTA to get, and I finally settled on the PL. To me, it seems to be a good compromise between focal length, portability and aperture. It will be perfect to get me back into observing once again. I think the mirrors will need collimating – that’s a given, right?? My daughter got me a collimating eyepiece and I have been reading up on how to do it – hopefully I can manage to do it without too many problems!! The tube has come with rings, dove tail bar, 10mm and 25mm eyepieces, a 2 x Barlow and a 30mm finder scope. I think I will be after a 90 degree finder at some point to make things a bit easier. I have mounted it onto my NEQ3-2 mount, and it balances ok. I think the mount it at is limit, but for observing it will be fine until I have saved for the HEQ5. Can’t wait to get it out under the stars, however, the weather forecast is cloud for the next week at least . . . sigh!! I guess that is the fabled curse of new scope owners everywhere!! So – lets hope that the clouds clear soon. I can see blue sky at the moment . . . just hoping it stays that way! Happy New Year everyone, and pop back again when the next entry will be following my first evening with the PL!! Cheers Nige
  19. 6 points
    It finally happened – after waiting two weeks and a day, the clouds parted, and I was greeted with a clear, still and cloudless sky!! Whoop Whoop!! 15 days is a long time to wait! The scope (SW Explorer 150-PL) had been sitting in my dining room since Christmas, and despite a very short outing last week, that lasted about 10 minutes, last night was the first time I used her properly. I popped the tube outside a good hour before I intended to go out to observe, giving it plenty of time to cool down. I then put the mount together – I did this inside, so I could see what I was doing! Once it was all secure and bolted together, I set the declination (?) to 53 degrees and took the whole thing outside through my patio doors. Before I popped the scope on the mount, I did a basic polar alignment. I was chuffed – I had the declination spot on, and just need a tweek to the left and it was there – not perfect, but enough for my first observing session. I then put the OTA onto the mount and secured it. I had been playing around with it in the house the previous week, and had found the balance point, and marked the dovetail bar, clever eh?! I then moved the counter weights about to get that balanced as well – it all worked out fine, and the lightest touch when the clutches were off was enough to move the scope about. I fitted the finder scope and got it aligned with tube – I did find this a bit tricky to start with, and a couple of times during the evening I managed to knock it out of true with my arm / head / face!! And I was now ready to go! My observing location is pretty limited at home – the front / side of the house is now flooded with light from an LED street lamp – the red circles show the street lamps, and the red cross is where I set up the scope. I had good views to the North and to the West though: I'm not shy to say that my knowledge of where things are in the night sky is limited!! This will change as the year progresses, so i content myself to first locate M31. I found this quite tricky - the finder scope is a straight through job, and the angles can sometimes make looking through it a challenge. So I bought out the 20 x 80's and quickly found it. I then pointed the scope in the same direction, and a few twists of the slo-mo controls and there it was. I had the 25mm eyepiece in and I realise that the target was waaaay bigger than the view through the eyepiece!! However, the core was revealed. I looked for quite some time, and small details began to come out and I'm sure I saw the darker dust lanes. I then took a look for the Double Cluster, and wow!!! What seemed to be hundreds of stars, packed into the view! I was getting happier by the minute! I content myself to just scan the star fields in that area for a while, and then swung around to try and and find M51. Using the 20x80 technique I found it, and turned the scope to it. It was a faint fuzzy at 48x, so I upped the mag to 120x with the 10mm eyepiece - it became a larger fuzzy object, and I couldn't really see any structure, but knowing the light coming into my eye had covered 20 million light years was awesome! It was getting late, so I took off the tube and carried it round to the garden with the street light over it - I wanted to look at M42 before I packed up. However, the glare from the street light overpowered the finder and I couldn't see anything. Tried to shield it with my hand, and although it stopped the glare, it was all a bit washed out. Shame - perhaps an air rifle would be a good investment . . . . . !! So, overall I thoroughly enjoyed my first night out with the 150PL. A few early observations on the scope and mount (this blog will be like a long term review for the scope): The OTA with tube rings and dovetail bar weighs in at 6.4kg / 14lb, according to my scales. This is right at the limit for the NEQ3-2 mount. Added to the weight, the tube is long at and although I got the balance spot on, it took several seconds for the vibrations to die down following focusing. However, using the slo-mo controls didn't induce any noticeable shaking when tracking objects, so thats a bonus! I think a heavier mount will be needed at some point. I hope to try and save for the HEQ5, but with daughter going off to uni in September that may be a while down the road!! The eyepieces and barlow that came with the scope appear to be fairly solid - I only really used the 25mm, and I have nothing to compare them too, but the view seemed bright and sharpe. The finder scope is a generic 6 x 30mm. While the view is crisp, trying to look through it gave me a cricked neck after a while!! A 90 degree finder will defo be required The dovetail bar is a lovely green colour, but does appear to be quite soft - just mounting the scope the few times I have used it as already left some marks and dints in it. The focuser is fine for my use - not stiff at all, and with enough friction to make small adjustments easy. I see no need to upgrade this yet. So - lets hope the weather stays clear, as I am keen to turn the scope on to the Moon!! Thanks for reading, and a Happy New Year to all!! Cheers Nige in Derby
  20. 6 points
    The aluminium tripods that come with a majority of beginner and mid-range scopes have had a bad name for years as being poorly made, sloppy and people have tried various ways to make them sturdier such as filling the legs with sand, lead shot, or even expanding foam. I just read an account the other day of where a person was fitting steel rebar into the legs to see if it will help… The only problem with these solutions is that you end up with a very heavy cumbersome tripod that is really no better than what it was when the modifications were started. I will show you what I do with these to help take the shakes out of them. The tripod modifications can be done to any of these aluminium tripods and not limited to adapting the SLT mount. Before starting the modifications, read the instructions thoroughly! If there is any part you are not sure of feel free to PM me. The tripods are manufactured cheaply and are not a precision work of art but can be fixed to be quite usable for only a few dollars. There are 3 different pivot points on the tripod that total 21 different places that the tripod can move so these can all be stiffened up. Tools required: Robertson or Phillips screwdriver Drill and ¼” and 1/8” drill bits Skilsaw Hacksaw or angle grinder Fine flat file White glue Paint or varnish of choice Socket/ combination wrench if using nylocks All the needed supplies should be available at a local hardware store. 18- #6 flat washers 18- #8 x 3/8” sheet metal screws 3- 1/4” x 3 1/2” bolts 3- 1/4” wing nuts or nylock nuts (preference) 6- 1/4” x 1” flat washers 6- 3/16” x 1” bolts 6- 3/16” wing nuts or nylock nuts 12- 3/16” x ¾ or 1” flat washers 1- 1/8” x ¾” aluminium flat bar (need about 9”) Container for all the old bolts and screws Note: If you wish to paint your tripod and mount I recommend a degreaser and an aluminium etching primer to help the paint adhere to the aluminium parts. For this I will show what I did to adapt the aluminium tripod to a Celestron SLT hub/mount. The supplied screws/ bolts holding everything together are cheaply made and it does not take much to strip these so all the hardware will be replaced with better quality. Start by taking the tripod legs off of the hub and set the hub aside as it will not be reused. Take the legs apart and remove all the factory screws/ bolts holding the cast metal pieces together. Check all of the plastic end pieces in the legs to make sure they are tight. If not they will need to be removed for now. You may wish to mark all the pieces so they go back together on the same leg but it is not essential. If you are going to paint your tripod/ mount now is the time to do it and give it a full day or two to properly dry. Use either #220 grit sandpaper or a course scotchbrite pad to scuff the metal to help it adhere to the parts. Do not forget to scuff the primer before painting! Now that you are ready to put the tripod back together we will stiffen up any of the plastic leg inserts if they were loose. The only piece you do not want to do this to is the top cap for the center leg. Do not install this cap or the center tray support brackets at this time. Put a bead of white glue around the inside of the leg where the insert goes and then push the insert into place. Using the new #8 x 3/8” (6 per leg set) screws, snug all the parts up. Picture 1: Set aside and let the glue harden. The #8 screws are slightly larger than the original size and will snug up nicely. You can see the difference in the photo above. I tend to reuse the lower single leg bolts as they are usually fine for this job. I use the glue on the insert and then the bolt. Before you reinstall the cast lower leg pieces run your finger around the hole that the center leg slides through, if there are any rough or sharp spots file them down smooth. Now that everything is dry start reassembly by installing the side legs and then slide the center leg up through the bottom. Set the legs aside for now. Now we get to the fun part, power tools! Using the 1/4” drill bit enlarge the holes on the SLT mount hub to match the larger hole in the tripod legs. Once done set this part aside. The next step is modifying the center tray supports. The supplied tripod tray is a flimsy piece of stamped metal and using the 3 original screws and wing nuts leaves much to be desired for tripod stability! Using 6 bolts in the tray will hold the legs firmly in place and not allow any play. Using the drill and the ¼” drill bit, drill a hole at the furthest end of the slot and another half the distance of the support. Picture 2: Now to make the new center tray. This tray will spread the legs out a bit more making alarger ground triangle which helps with stability. I used a piece of 3/8” plywood with dimensions of 15 3/4” on the flat side and 13 5/8” flat to peak. Your 2 holes should be approximately 2 ½” and 5” from the peak. Drill ¼” holes and set aside for now. TIP: Use the tray support as a template to mark out the holes to ensure alignment. Picture 3: Using the aluminium flat bar cut 3 pieces 2 3/4” long. Use the file to smooth and round off the edges of the piece. (I used the edge of a quarter as a template to round off the corners.) Now to reassemble the tripod! Take a leg assembly and lay it flat on your work surface, insert the center leg cap at this time but do not screw it into place. Take one of the flat bar pieces and lay it across the legs butted up against the lip of the center cap and mark out the location of the screw hole on the flatbar. Using the 1/8” drill bit make a hole and then install this with the center cap. If you have ever noticed on these tripods, as soon as you put some weight on them the center leg tends to slide/ lean inwards which causes only a small part of the leg to actually be making full contact. This flatbar brace will keep the center leg inline with the other legs when the scope is mounted. Picture 4: Optional: I drill a second hole and rivet it into place so that the flatbar cannot loosen off and the cap can still be unscrewed and removed if needed. (3/16” drill bit and 1/8” rivet) Once the flatbar is attached turn the leg section over and it is time to install the tray brace. Screw one of the pin brackets onto the leg and then insert the pin. Put 3 of the #6 flat washers on the pin and then slide the tray bracket on (flat side up). Install 3 more #6 flat washers and then the other pin bracket. Screw bracket into place. The tray support bracket should be nice and snug between the brackets now and there will be no slop for it to slide around on the pin. Repeat for other legs. Picture 5: So now the tripod should almost be done, take the mount hub and install the new 1/4” x 3 1/2” bolt. At a minimum you should have a flat washer under the bolt head and one under the wing nut. Check the gaps between the legs and hub to make sure they are in full contact with each other. If there are gaps between the legs and hub use 1 or 2 appropriate thickness washers to fill the gap. Plastic report covers can be cut to make washers if the gap is small. You want the legs parallel but not squeezed to the point you cannot adjust the center leg smoothly. Use a 1/4” x 1” flat washer and then your choice of either a wing nut or nylock to tighten things up. Tighten until the leg is stiff but can swing without fighting it. Repeat for the other legs. You should now have a complete tripod minus the tray. Final step is to install the tripod tray using 2- 3/16” x 1” bolts and 4 flat washers for each leg. I use one washer on top of the tray and one underneath the bracket so you can tighten these up very well with the wing nuts or nylocks. Picture 6: You should now be the proud owner of a very stiff aluminium tripod that no longer has a bad case of slop/ shakes when you put your scope on it.
  21. 6 points
    Toot and I had a wonderful week with Olly and Monique in the Haute Alpes. We enjoyed the magnificent dark skies, the stunning Milky Way, looking through Olly's big Dob and drawing and painting with Monique. We saw for the first time: The Crab Nebula, The Swan Nebula, The Eagle Nebula and all of the Veil Nebula. The Witches Broom was fantastic and through a wideangle eyepiece and Olly's monster of a Dob it appeared almost 3D. We also looked at the Lagoon and Triffid Nebulae before they dropped below the horizon. From our backyard and through my 127mm. refractor, we quite often look at M13 but such views were no preparation for the visual trreat we had through the big Dob at Les Granges. Blew our socks off! The skies were really dark and each clear night, I treated myself to a couple of hours taking unguided photos with my Canon 400d DSLR mounted on a travel tripod. I have attached a selection of images from our week. During the day Olly helped me improve my very basic astro imaging digital skills. The man has considerable patience! He also took me through an imaging run using side by side mounted refractors to capture several hours worth of colour and luminance data of M33. Whats more I got to take home the data to practice my new learnt skills. At some stage my version of the M33 data will appear in my gallery. We really enjoyed our stay at Les Granges, Olly and Monique are very nice people and excellent hosts. I cannot think of a better place to enjoy and image the night sky. During the day and if you can pull yourself away from the laptop, the landscape is spectacular, there are plenty of opportunities for walking, cycling, climbing, birding, photography, painting and even collecting fossils. A great place for both strenuous activiy and rest. Thanks Olly and Monique
  22. 6 points
    Well after what seems like an eternity,ive finally broken through 10mm depth of sagittal on my 22" grind!!!another 2mm or so to go which will hopefully be done by the end of the weekend and its tile tool time.been some clear skies this last week or so and with virgo up well ive missed galaxy hunting but it will be worth it when the beast is ready!!!! Happy days. clear skies Rich
  23. 5 points
    This was taken 8th April 2016 from an apartment in Hamilton Island, Australia. The equipment I used was a Samsung Galaxy S5 and an old but good quality pair of binoculars left by the owners. The skies were incredibly dark and we were able to attend a talk by a local astronomer who guided us around what could be seen with the naked eye. I was delighted last year when I used Stellarium last year to look at the view on that date and confirm that I had indeed captured Jupiter and 4 moons!
  24. 5 points
    Toot and I had a great time in Norwich last night. Dr Michael Foale CBE gave a talk about his life as an astronaut to a packed audience at the University of East Anglia. What an accomplished, kind and measured man. A couple of hours in his company passed very quickly. He has great interpersonal skills and although we only spoke to him very briefly, both my partner and I felt we had 'met him' rather than just 'heard him' speak. What an exciting, if not at times scary, life and career he has had? Highlights include: a spacewalk to upgrade the Hubble Space Telescope's computer from a 386 to a 486 ( I had one of each but I only had to fetch them from Currys) stopping the MIR space station from spinning out of control after it had been hit by a supply vessel commanding the International Space Station There were many children in the audience who were very interested in space and science. Dr Foale encouraged them to do what they were good at, pursue their dreams and not to be deterred by setbacks. He paid particular care to encourage girls to pursue careers in science and aerospace. He very kindly - let anyone who wanted to - have their photograph taken with him. A long queue of excited children formed down one side of the Lecture Hall. "Dr Foale, I could tell you that the photograph is for my grandchildren, but really its for me" said a very excited and pleased old man. If you get a chance to hear him speak and/or go to events organised by ISSET or a 'Pint of Science' - go for it!
  25. 5 points
    Source: Sgl - How To Use The Blogs
  26. 5 points
    ImPPG has moved to GitHub: http://greatattractor.github.io/imppg/ ImPPG performs Lucy-Richardson deconvolution, unsharp masking, brightness normalization and tone curve adjustment. It can also apply previously specified processing settings to multiple images. All operations are performed using 32-bit floating-point arithmetic. Supported input formats: FITS, BMP, JPEG, PNG, TIFF (most of bit depths and compression methods), TGA and more. Images are processed in grayscale and can be saved as: BMP 8-bit; PNG 8-bit; TIFF 8-bit, 16-bit, 32-bit floating-point (no compression, LZW- or ZIP-compressed), FITS 8-bit, 16-bit, 32-bit floating-point. ImPPG can also align an image sequence, with possibly large and chaotic translations between images (aligned output images preserve number of channels and bit depth). This can be useful, for example, when preparing a solar time-lapse animation, where subsequent frames are offset due to inaccurate tracking of the telescope mount. Other possible applications are smoothing out of terrestrial landscape time-lapses or preparing raw frames (with serious image jitter) for stacking. ImPPG is free and open-source, licensed under GNU GPL v3 (or later). Building from source code (C++) requires Boost, wxWidgets and (optionally) FreeImage & CFITSIO libraries and is possible on multiple platforms. Windows executables (32- and 64-bit) can be downloaded using the links below. See the README file for details on usage and building. Screenshots: Sample results (processing and animation alignment): Image processing tutorial Solar processing tutorial by Michael H.F. Wilkinson Astrobin users can add ImPPG to their “Gear” list: imppg Files: imppg-src.zip: source code imppg-win32.zip: Windows program (32-bit) imppg-win64.zip: Windows program (64-bit) If you are not sure what you need: download the latest imppg-win32.zip, unpack it and run imppg.exe. Version 0.5 and newer: go to http://greatattractor.github.io/imppg/ Version 0.4.1 (2015-08-30) Enhancements: – Numerical sliders use 1-pixel steps instead of hard-coded 100 steps – Output format selected in batch processing dialog is preserved – Unsharp masking not slowing down for large values of "sigma" – Increased the range of unsharp masking parameters Bug fixes: – Invalid output file name after alignment if there was more than one period in input name – Crash when a non-existing path is entered during manual editing – Program windows placed outside the screen when ImPPG was previously run on multi-monitor setup – Restored missing Polish translation strings imppg-src.zip imppg-win32.zip imppg-win64.zip Version 0.4 (2015-06-21) New features: – Image sequence alignment via solar limb stabilization – FITS files support (load/save) – Zooming in/out of the view Enhancements: – View scrolling by dragging with the middle mouse button – Logarithmic histogram setting is preserved Bug fixes: – Tone curve in gamma mode not applied during batch processing imppg-src.zip imppg-win32.zip imppg-win64.zip Version 0.3.1 (2015-03-22) New features: – Polish translation; added instructions for creating additional translations Version 0.3 (2015-03-19) New features: – Image sequence alignment via phase correlation Enhancements: – Limited the frequency of processing requests to improve responsiveness during changing of unsharp masking parameters and editing of tone curve Bug fixes: – Incorrect output file extension after batch processing when the selected output format differs from the input Version 0.2 (2015-02-28) New features: – Support for more image file formats via FreeImage. New output formats: PNG/8-bit, TIFF/8-bit LZW-compressed, TIFF/16-bit ZIP-compressed, TIFF/32 bit floating-point (no compression and ZIP-compressed). Enhancements: – Enabled the modern-look GUI controls on Windows Bug fixes: – Selection border not marked on platforms w/o logical raster ops support (e.g. GTK 3) Version 0.1.1 (2015-02-24) Bug fixes: – Blank output files after batch processing when L-R iterations count is 0 Version 0.1 (2015-02-21)
  27. 5 points
    Last night, I stood and watched as my ten year old grandson looked through my old 10x50 binoculars and found for his first time; the Andromeda Galaxy and then the Pleiades. Looking out into space and back in time is and should always be very exciting! He was very pleased with himself. Binoculars are a great way into astronomy for the younger child. Negligible set up and minimal supervision required - wide variety of observeable treats and maximum time taking in the view! Have set him a challenge to find the monthly binocular highlights in my astronomy magazine and am looking forward to his reports..
  28. 5 points
    Originally I wrote this article in early January of this year so some bits may be out of date by now but I don’t think it really matters. Also if I were publishing these articles in the order they were originally written this one should be about astro-photography but given the recent comments by Brian Cox around his thoughts on the existence of extra-terrestrial life I thought while it was topical I might as well put forth my musings on the subject. The picture near the end of the article comes from wikipedia so I can’t say how accurate it is but I think it is close enough for the point it's trying to make. I'm also not entirely sure how the picture will come out but hopefully it will be legible. I wonder if this year will go down in history as the year mankind discovers that we are not alone in the Universe. With all the stuff we have going on at the moment you’d think we were getting close to an answer. The number of extra solar planets discovered has now reached one thousand and data from the Kepler spacecraft continues to redefine our view of how many earth like planets there may be lurking in our galaxy as well as just what the extent of a habitable zone around a star might be. Not only that but we also have NASA’s nuclear powered curiosity rover that was delivered to the red planet in a way that wouldn't have looked out of place in an episode of Thunderbirds. Although its primary mission isn't to look for life, having a rover the size of a Mini trundling around the red planet drilling rocks, analysing samples and vaporising bits of scenery with its laser will hopefully stand a good chance of proving whether life has ever existed there. Most recently we have the news that the Rosetta spacecraft has woken up on its way to chasing down comet 67P/Churyumov-Gerasimenko in order to land a probe on it. It is all tremendously exciting stuff which you’d hope might just mean that this is the year we finally answer that cosmic conundrum. It really would be mankind’s most stunning scientific discovery if we could finally put that question to bed with a ‘no, we’re not alone’ answer and move on to more entertaining thoughts such as ‘What do our alien neighbours look like?’, ‘What sort of weapons do they posses?’ or even ‘I wonder how they’d taste with some fava beans and a nice Chianti?’ Discussing the possibility of extra terrestrial life though can be problematic because it sometimes leads to the sort of conversation that involves believing aliens are whizzing around our planet turning cows inside out and probing the kind of people that turn up on The Gerry Springer show or Jeremy Kyle. However that does I suppose help to frame the range of possibilities and their probabilities. So at one end you have simple organisms such as bacteria which could be very likely to exist on other planets or moons, to the other extreme of having technologically advanced, bovine bothering aliens whizzing around in spaceships which almost certainly do not. Personally I very much subscribe to the idea that there are alien life forms of some sort out there. I hope life turns out to be quite common in the universe as long as a planet’s star is capable of simmering a soup of water and organic chemicals for a few billion years. But the question of intelligent life is much trickier because while it may be that creating simple organisms is a fairly easy task, where things go from there is purely driven by evolution so it is both a slow and fairly random process. We know this for ourselves because if not for the fortuitous catastrophe of a huge asteroid or comet hitting the earth a few million years ago and helpfully wiping out the dinosaurs we almost certainly wouldn't be here now. While any discovery of extraterrestrial life would be exciting it is really intelligent life, perhaps one with a technology like ours or even greater than ours that most people find appealing, but what are the odds? Well, if we look at the Earth, current estimates put the number of species on the planet today at around the 9 million mark and that doesn't include bacteria or other micro-organisms. If you add in everything that has ever existed on earth over the eons I don’t think it unreasonable to add a couple of zero’s to that figure but we can say with some certainty that we are the only intelligent creatures to have evolved so far. Sure we are told dolphins are pretty smart but since they live in an ocean with only a pair of flippers and a tail to work with it’s difficult to imagine how they could ever discover fire, need to invent the wheel or experiment with electricity. And look at our closest relatives the apes. Practically identical to us at a DNA level and in possession of those handy opposable thumbs yet the height of technology that our simian cousins have developed so far appears to be using a stick to go fishing for ants. So it would seem that we are at the very least something of a billion to one chance. That does sound like pretty long odds, but given the vastness of our galaxy never mind the universe, astronomical odds would still suggest we are not alone in being the only intelligent, technological race out there. But if there are intelligent civilisations out there why have we not heard from them? After all we've been beaming them high quality entertainment in the form of radio and television broadcasts for years. Well, to put that into perspective check out the picture below that shows how far we've been spamming Dr Who and Downton Abbey to anyone with the antenna to listen. That tiny blue dot isn't the earth, it is in fact what a two hundred light year radius around the earth looks like in our Milky Way galaxy and it’s really not that impressive is it. No surprise then that we've yet to receive any communications requesting an answer to Who shot JR? It does really highlight the scale of the problem though. Distances within our own galaxy are so vast that even the speed of light is a bit sluggish if we’re hoping to detect stray radio emissions from another world. Still, it’s good to be optimistic and even though the odds may be very, very long, we might yet be lucky and pick up Rigel’s got talent sometime soon. Personally I think it will be more exciting when we put some technology into space that will allow us to observe the chemical signatures from exoplanets atmosphere with sufficient accuracy to determine the elements that are present and in what volumes and therefore infer the presence of biological entities. Having the capability to do that should allow us to detect signs of life on planets where the local wildlife exists but is either too stupid or too lazy to come down from the trees and kick off a technological revolution by making fire and inventing the wheel. Although it may just be that our extra terrestrial neighbours have been so traumatised by the attentions of intergalactic, joy riding aliens and their probes that they’re much happier to stay in the tree tops and hope the rest of the galaxy doesn't come calling.
  29. 5 points
    This is the first of a series of articles I wrote for my local astronomy society (CLASS) newsletter that I thought I'd post here. They are not meant to be a serious attempt to tackle any of the subjects with any sort of authority. I was aiming more for an entertaining series of articles on the kind of trials and tribulations that are common to amateur astronomers. Or as I recently introduced one of my articles "It's the usual mix of pop culture references and dubious facts wrapped around a vaguely astronomical theme" O Andromeda, Andromeda, wherefore art thou Andromeda? One of the first things you're going to want to look at when you buy a telescope is the Andromeda galaxy. You'll have seen the photo's in the astronomy magazines or on the internet and be filled with excitement at the thought of looking through your new toy and gazing upon a beautifully detailed galaxy that will fill you with awe and make the several hundred/thousand pounds you spent seem like the bargain of the century. If only it were so. Let's first address the disappointing reality, you won't see anything like the images from the magazines, in fact you can simulate the actual visual observation of the Andromeda galaxy and avoid the frustrating search for it thus. Step 1. Sneeze on a window pane. Step 2. Observe the resultant mess through a plastic magnifying glass you won in a Christmas cracker whilst standing ten feet away in a fairly dark room. Congratulations that strange, blurry blob you can just about make out looks exactly like the Andromeda galaxy will if you can ever find it with your telescope. The problem with Andromeda is one of expectation. You've seen the pictures, you've read the article that says it’s actually three times the width of the full moon (or something). You will imagine therefore that you'll only have to point your telescope somewhere in the general direction and it will leap out at you in glorious Technicolor. What will in fact happen is this. You'll start by casting around in the general direction hoping to stumble across it. You'll continue with this method for a while and depending on how enthusiastically you swing your scope around you'll probably discover the double cluster in Cassiopeia. Congratulations this is the first step in finding this elusive galaxy. Not because Andromeda is really close to the double cluster but simply that the happy mistake of finding this beautiful object will sustain you through the dark, frustrating hours to come. Next you'll attempt the methodical approach of star hopping. Taking out your torch you'll shine it on a printout of the constellations and you'll work out where you need to look. Stare hard at the picture to burn it into your mind. Look up and try to orientate yourself as the details of what you're looking for leak out of your brain. Go back to the torch, stare hard, lookup. Repeat until you're certain you have hopped from star to star and you’re definitely, positively in the right place. You will be looking in the wrong place. Accept this fact now, it will save time. Due to light pollution in your garden you'll be at least one star away from where you should be. You'll look through the eyepiece anyway and it won't be there. At this point you'll wish you'd handed over more cash for the GOTO option you didn't buy because you thought it was cheating. You'll try and use the finder scope and see too many stars but without it you'll see too few. You'll wish you'd at least bought a red dot finder; they're only £20. You'll have another look at the double cluster as now you've stumbled across it once you can find it again easily and you'll calm down and resume your search for Andromeda. Many hours later you’ll manage to stumble across a strange blurry blob that will look nothing like the pictures in the magazines and decide you’ve finally found it. You’ll check the view through the finder scope and be able to see it clearly in there too and wonder why it took so long. You’ll look at where your scope is actually pointing compared to where you were originally looking and realise you were several stars and about a million light years away from the correct spot. And then the magic happens. You’ll feel a sense of achievement certainly but once that has passed you’ll think about what you’re actually looking at. OK it’s a fairly indistinct blob in your eyepiece but since you have seen the stunning pictures in the magazines you know precisely what you’re looking at; a complete other galaxy almost identical to our own made up of a trillion stars and many trillions of planets (probably). Some of those stars are just like our own sun and some just as old and standing there alone in the dark you’ll wonder if there’s someone on a planet somewhere in Andromeda struggling to find the milky way and deciding they need to start saving up for a GOTO mount too.
  30. 5 points
    Sat24 showed a three hour gap in the clouds and gave me enough time to explore day 13 of the moon.... The three named craters in this sketch show along the terminator. The largest crater at the top is Pythagoras, 130km in diameter with steep 5000m cliffs and a double central mountain (although only one showed at the time of the sketch). Oenopides is next with steep terraced cliffs, 68km at its widest point and suffers the same crushed walls as Pythagoras from the walled plain Babbage in the centre. Right at the bottom of the sketch is Markov the smallest crater at 41km in diameter and with 2400m cliffs. Telescope / 4" f/11 Lyra EP / 3/6mm Nagler zoom at 6mm x183 Temp / 2˚C Transparency / average Antoniadi III Colongitude 65.6˚ Phase 26.6˚ Lunation 12.99 days
  31. 5 points
    The Double Cluster - Caldwell 14 The Double Cluster or Caldwell 14 in Perseus is a visual extravaganza and probably one of the most breath-taking sights to be seen in the night sky. On a good night the soft glow from the combined light of the two individual clusters resolve into an awe-inspiring swarm of literally dozens upon dozens of blue and white stars surrounded by just as many unrelated Milky Way stars. The true brilliance of the Double’s stars are dimmed by swaths of heavy galactic dust clouds between ourselves and the two clusters which render their members over four times fainter than they really are. In these terms, it has been estimated that if the Double were located at a similar distance of the Pleiades (some 407 light years away), about one quarter of our northern sky would be filled by its stars and hundreds of its members would shine more brilliantly than the planet Venus. NGC 884 and NGC 869 are located at distances of some 7,600 and 6,800 light-years from Earth respectively and thus are physically close to one another in space. Both clusters are found in the Perseus Arm of the Milky Way - we ourselves are riding the Orion Arm – and are about 5.6 million years and 3.2 million years old respectively. If we consider that an open cluster like that of Pleiades is thought of as a young cluster with about a 100 million years of age, then clearly the Double is a mere infant in cosmic terms. The Double’s stars formed at approximately the same time and from the same primordial molecular cloud of dust and gas. Spectroscopy has revealed that many of the stars have a very high concentration of heavy elements and typically are super hot and very luminous O and B types. These massive stars are aging very quickly and few will live to a billion years; instead they will eventually self destruct into supernova, creating shock waves powerful enough to disrupt the already two loosely bound open clusters and disperse their stars. In consequence, the Double will probably be unrecognizable as a cluster within 250 million years or so. The sketch itself was a tad complicated to complete and no doubt is not entirely accurate. These two clusters are quite complex to sketch due not only to the sheer amount of visible stars seen and the sense of differing stellar magnitude but also in the beautiful variation of colour observed at the eyepiece. The best plan of approach was to draw up a target-clock-face with 45º angles and concentric circles and use this as a template. To achieve some sense of variation in star magnitude I used an ink-pen for the brighter stars and various grades of pencils for the dimmer stars ranging from 4B to B. Over the sketch was taped a piece of tracing paper to which I noted the more prominent star colours on the overlay. To capture the best possible field of view with the 4” f10, I used the lowest magnification I have in my collection, namely, a Celestron LX 25mm.
  32. 5 points
    Some Doubles in Andromeda Perhaps there are some who think doubles are merely two stars close together and they may be right, just as one may be right in saying great music is only a bundle of notes strung together or that literature is just a large collection of words. But as with most things in life, if you spend time with doubles, hunting them out and learning from them, you come to realise that the grand majority radiate an aesthetic beauty quite unlike anything else. As with any art, there need not be any purpose in splitting stars, just as there need not be any necessary purpose in strolling through a forest at dawn, viewing a beautiful sunset or writing a poem to your loved one, but we can also highlight some of the more utilitarian reasons for undertaking such a pursuit: star systems are among the very few objects in the night sky to show you any real colour, in some cases majestically bright and vibrant. This gives the pursuit a rather pleasing aesthetic appeal. tracking down doubles gives you excellent practice in the art of star hopping and in reading and using star maps and charts. seeing conditions will often influence your success, so by observing doubles on different nights you can gain familiarity with how how appear in your telescope under varying conditions. like lunar and planetary observing, you can observe doubles from your own garden or roof top under quite heavy LP, so you don’t need to be hanging around for perfectly dark nights or sites. searching for double stars teaches you something about your telescope’s resolving power, its ability to provide you sharp and detailed viewing, even of objects that upon initial appearance come across as a single source of light. by comparing the double and multiple star systems you can practice your understanding and skills at recognizing differing star magnitudes. Andromeda is a fascinating constellation in itself with many beautiful objects to discover. The following are a few sketches of some of the wonderful double stars it conceals. I hope you enjoy them and I will see you all after a little holiday break. Should be back at the end of the month. Bye for now.
  33. 5 points
    General Plan I've decided to include my general observing plan for the warm summer months ahead because I feel it will not only help direct my own observations and studies but may also help other folk trying to decide what urban wonders they might be able to try for in the following weeks. The listing information includes Messier objects, NGC wonders, and Double Star gems which I think are worth taking a shot at even if the possibility of success isn't 100%. Unless directed otherwise the listing will be set out as follows: Target Name: Constellation; Type; Level of Subjective Difficulty 1 (relatively easy) to 4 (very difficult). The Messier List M 13: Hercules Globular Cluster 1 M 92: Hercules Globular Cluster 2 - 3 M 29: Cygnus Open Cluster 2 M 39: Cygnus Open Cluster 3 - 4 M 5: Serpens Globular Cluster 2 M 16: Serpens Open Cluster 1 M 10: Ophiuchus Globular Cluster 2 M 12: Ophiuchus Globular Cluster 2 M 19: Ophiuchus Globular Cluster 2 M 62: Ophiuchus Globular Cluster 2 - 3 M 107: Ophiuchus Globular Cluster 2 - 3 M 57: Lyra Planetary Nebula 1 M 56: Lyra Globular Cluster 3 - 4 M 27: Vulpecula Planetary Nebula 2 - 3 M 71: Sagitta Globular Cluster 4 M 8: Sagittarius Galactic Nebula 1 M 17: Sagittarius Galactic Nebula 1 M 20: Sagittarius Galactic Nebula 3 M 21: Sagittarius Open Cluster 3 M 23: Sagittarius Open Cluster 2 - 3 M 22: Sagittarius Globular Cluster 3 - 4 M 25: Sagittarius Open Cluster 2 - 3 M 28: Sagittarius Globular Cluster 3 - 4 M 54: Sagittarius Globular Cluster 4 M 55: Sagittarius Globular Cluster 3 - 4 M 11: Scutum Open Cluster 1 M 4: Scorpius Globular Cluster 2 M 80: Scorpius Globular Cluster 3 M 6: Scorpius Open Cluster 1 - 2 M 7: Scorpius Open Cluster 1 - 2A Few New General Catalogue (NGC) Wonders NGC 6235: Orphiuchus Globular Cluster 4 NGC 6572: Orphiuchus Planetary Nebula 2 - 3 NGC 6910: Cygnus Open Cluster 2 NGC 6866: Cygnus Open Cluster 3 - 4 NGC 6819 Cygnus Open Cluster 2 - 3 NGC 6826 Cygnus Planetary Nebula 1 - 2 NGC 6834 Cygnus Open Cluster 3 - 4 NGC 6830 Vulpecula Open Cluster 3 - 4 NGC 6823 Vulpecula Open Cluster 2 - 3 NGC 6302 Scorpius Planetary Nebular 1 - 2 NGC 6543 Draco Planetary Nebular 3 - 4 Double Stars: The Little Gems The listing information will be as follows: Target Name: Constellation; Folk Name Kappa Herculis (k Her) - - - - - Hercules - - Marfik, Marfak, Marsic (The Elbow) Alpha Herculis (α Her) - - - - - Hercules - - Rasalgethi (Head of the Kneeler) Alpha Scorpii (α Sco) - - - - - Scorpius - - - Antares (The Anti-Mars) Beta Scorpii (β Sco) - - - - - Scorpius - - - Acrab Beta Cygni (β Cyg) - - - - - Cygnus - - - - - Albireo (The Hen's Beak) 61 Cygni - - - - - - - - - - - - -Cygnus - - - - - Bessel's Star Epsilon Lyrae (ε Lyr) - - - - -Lyra - - - - - The Double Double Zeta Ursae Majoris (ζ UMa) - - - - - Ursa Major - - - - Mizor & Alcor Alpha Ursae Minoris (α UMi) - - - - - Ursa Major - - - - - Polaris, (The Pole Star) Alpha Canis Venaticorum (α CVn) - - - - - Canes Venatici - - - - - - Cor Caroli Epsilon Boötis (ε Boo) - - - - - Bootes - - - - - Izar & Pulcherrima (The Veil & The Loveliest) Mu Boötis (μ Boo) - - - - - - - - Bootes - - - - -Alkalurops Gamma Delphini (γ Del) - - - - - Delphinus - - - - - Job's Coffin I hope this helps in some manner of ways :bino2:
  34. 4 points
    Hi all Been a while since I added to my blog. To be fair, not really had much to report! I have been out of furlough for over four weeks now, and with nearly 2000 of our Greene King pubs reopening in the space of a week recently, the last three weeks have been manic! We have a reduced team, but have all pulled together and got each site across the line! I would like to say things are slowing down a bit, but that just doesn't seem to be happening! But I'm not complaining - happy to be busy again! All this work had meant I have not been out under the skies for some time now. Sure, the weather hasn't been very cooperative, but on the odd evening where the clouds have cleared, I have just wanted to go to bed! So, I made a conscious effort that this weekend would be different. I had been keeping an eye on Clear Outside all week, and Sunday looked like the best evening. I wanted to see the comet, so decided I would make a trip into the Peak District (I live in Derby), to find some darkness! So, at around 10pm, with a still bright horizon, I hopped in the car and made my way to Thorpe Cloud near Ilam - an area a few miles North of Ashbourne. The car park I used to use when I came here to do some Landscape photography has now got a barrier across it, so I had to park about a mile away and walk back. Note to self: Next time, pack a torch so I don't have to use phone! Here is a light map of the area. Am surprised its Bortle 4 here - thought it darker than that: The 30 minute walk across the side of Thorpe Cloud gave my eyes time to become dark adapted. On the way round, I saw a pass of the ISS. Was as high as I remember ever seeing it, and it was very bright. I checked this morning, and it was -3.4!! I took my time and drank in the Milkyway over head, with Cygnus buried deep in the star clouds. I came round the side of the Cloud and there it was! Nestled just above the horizon below the pan of Ursa Major! I needed averted vision to see it with my naked eye, but when I turned the 20x80's on it - WOW!!! The most amazing site. I have not seen a comet since Hale-Bopp, so this was a special moment for me. I spent a good half an hour on the bins, and then decided to try and take some photos. I will freely admit that I am at the very start of my AP journey. I have a Canon 400D, and a fixed tripod for widefield, while my EQ3-2 is manual right now. Using the 500 rule theory, at 17mm on my 17-55mm f2.8, I worked out I could get 18 seconds exposures before trailing would be really evident. I opened the lens wide, set ISO to 800 to try and reduce noise and set the shutter at 15 seconds and started snapping away. When the first preview appeared I was quite pleased - there was the comet as I had seen it through the bins: Yeah, I didn't nail the focus. Difficult with nothing to actually focus on, and only a small (non-live view) screen to look at! However, if you squint a bit they look ok! The wider shots are better: It was getting late, and I had to be up at 6am, so started to head back to the car. It was then the ISS came over for pass #2 of the evening. Very much the same brightness, and I followed it across the sky. I had put my camera away by this point, otherwise would have taken a long exposure of it going over. Got back to the car, and headed home, getting in at about 2:15am, and went straight to bed. I intend to run these images through Photoshop this evening and try and pull put some more detail. I am also going to try and stack some of the images I took! Thanks for reading all! Nige
  35. 4 points
    Perhaps the open outlook to the east Ensures the leaded panes catch every ray And part explains why on the dullest day My eye is drawn up to the colour feast, After a rubbish couple of months, finally a holiday........a week in the Yorkshire Dales, only a 7.5 hour drive from Kernow but worth it! A little cottage east of Hawes, nothing but sheep and pheasants and yes dark skies. Great food in small pubs with the friendly locals, Abbey ruins visited and gloriously recommended to sooth the soul and switch off the rat race (Easby Abbey nr. Richmond, Jarvaulx Abbey nr. Ripon), honestly THE best chips from The Chippie in Hawes and of course beautiful scenery! With not much room in the car (have to take the family not just the scopes?) I only packed the Heritage 100P and my BST eyepieces, opposite to my home viewing where I can only see the southern sky, here it was the West and North, typically for me the cottage had the only street light for at least 100 miles to the south.....still new things to spend time on........ So two clear nights.....once I got over the nervousness of total dark away from civilisation and wild animal noises I've never heard before....out with the little dob Auriga....the 3 open clusters, M36/37/38, even with a waxing moon, still was able to pull these out, have to say that the 12mm BST is turning out to be a particular favourite, reckon I could make out about a dozen of the brightest stars in the pinwheel cluster. Stars Capella and El Nath (start the Taurus debate here...) a lovely distraction....now if I hadn't taken the wife and son would I have seen the famous nebulae with my 8" Dob? On to Cassiopeia....and after the owl cluster.....and what a revelation. The first time viewing and frankly spent far too long staring at this beauty....actually think I could see it in my sleep that night! The whole constellation was a wonder confirming I need to be less lazy and get my scopes to local dark skies more often......just don't let work life get in the way Spent a fair bit of time viewing the moon, decent views with 5mm BST, and just staring up with my eyes at a dazzling dark sky full with stars. All in all a wonderful week, great days out, dark and clear skies at night, great food (and drink), if you get the chance, pack away some clean undies and a scope and head to the Yorkshire Dales (If you're interested...opening lines are from a poem called east window by Alan Hartley relating to a stained glass window in Leyburn)
  36. 4 points
    Invited by two of our children and grandchildren to meet them, early on Christmas morning, on the beach at Southwold for a swim. Had serious misgivings about this: as I dont do getting up early, I do not have a wet suit and recently have been under the weather. Anyway as my partner does have wet suit and was keen, a few bah-humbugs thrown in my general direction got me out of my 'toastie slumber chariot' before 8:00 UT and by 10:00 we were at the water's edge. There had been a hard frost overnight but by the time we entered the water, the air temperature was a balmy 2 deg C . I managed a brisk 2 minutes before I fully realised why in previous years I had restricted swimming in the North Sea to the months of June, July, August and September. Enjoy your Boxing Day Stargazers George thankfully no longer in the North Sea and in Lowestoft
  37. 4 points
    I'm starting with an empty area about 10 x 4 metres between sun lounge and observatory in front of living room window and facing roughly south. I have killed off most of the weeds and grass by covering with an old tarpaulin for a year or so. This has also stopped the ground from drying out and making it easier to dig. In addition to providing a path to the observatory, this will provide flowers and shrubs to see from the living room window. Plus a small pond and fountain. The latter is something I have been working on in 3D printing and plan to have something unique. Apart from the pond there will be planting areas and slabs and ornamental stepping stones. I have removed most of the tarpaulin and started digging a hole for the pond. The latter is a pre-formed pond I bought from Amazon :- Bermuda Sand Pre Formed Pond 128 x 84 cm. Here are some photos of pond hole digging and the general area.
  38. 4 points
    Every Autumn our local pub organises a charity auction evening. As one of the lots I offer a voucher for 'An evening of Astronomy'. This blog shows the outcome of the last winning bid as posted on the local website, warts and all. Cashing in on photons A short article on an outreach at the Bishop Monkton observatory Sunday the 22nd of October 2017, a week after the annual auction at the Lamb and Flag, the owners of the Astronomy Evening voucher from 2016 made it to the observatory. It may have taken a year to arrange but that’s nothing to the 2.3 million year old photons hitting our eyes from M31, the Andromeda galaxy. The author’s own image of M31, the Andromeda galaxy. This was just one of the sights I was able to show to my guests, Carole, David, Stancey and Olly. What great companions they were too being very patient as I waffled on about the secrets Andromeda gave up to Edwin Hubble and the scientific community in the early 1920s. Showing the attentive audience how to star hop just with their eyes from the great square of Pegasus to a large fuzzy patch overhead was all it needed. Until then most astronomers believed everything we could see was contained within our own galaxy, the Milky Way. How much further from the truth could that have been, as we now know it is merely in our backyard in astronomical terms. Testing the sky was also on the agenda for the evening and the conditions were such that we could just make out the seven main stars of Ursa Minor with normal vision. That equates to a magnitude 5 sky so not too bad but how much better it could be without all the untamed light around us. Olly, pointing at the Pleiades, remarked that he always thought that was Ursa Minor. An open cluster, number 45 in Messier’s catalogue, known as the Seven Sisters or Subaru in Japan is a very young, close group of hot white/blue stars formed from the same cloud of gas. The author’s own image of the Pleiades (M45). We had to crack on though and put to use the short, telescope driving lesson undertaken under red light and over a glass of wine earlier in the kitchen. I wanted to make sure we didn’t miss a chance to view M13, the Great Hercules globular cluster before it sank below the rooftops. It proved a bit of a tough nut to crack because to get the most out of it we had to use a technique called averted vision. David realised that the large fuzzy ball in the eyepiece was made of thousands of stars, bound together by their own gravity like a swarm of bees around a honey pot. These 12 Billion year old stars though take us back to the very start of the Universe. M13, the Great Hercules globular cluster (Wikipedia commons credit; rawastrodata.com). It was time to move on to some other deep sky objects so we dipped into the space between Perseus and Cassiopeia to sample the double cluster that is pretty in itself but I wanted my audience to look a bit deeper. Our eyes are poorly equipped compared to cameras but obvious to all is a rich, orange star apparently visiting the cluster of younger members. Colour tells us so much about a star and so we chased Cygnus the Swan across the Milky Way with both ‘scopes to pinpoint Alberio, the star designating the swan’s head. In the ‘scope everybody detected Alberio as two stars of sharply contrasting colours, an optical double, often described as indigo and gold telling us immediately that they have markedly different surface temperatures and characteristics. Are they gravitationally bound as a binary system? Well the jury is out on that one but current estimates have one third of all stars in the Milky Way to be true binaries. Getting towards the end of the evening it was time for a couple of more challenging objects. Number 57 in Messier’s catalogue is described as a planetary nebula purely because when viewed in the 18th century it resembled a view of the know planets, small, round (ish) and some colour. These objects have nothing to do with planets but are the result of the after effects of a dying star that has puffed off its last layers of gas leaving a white dwarf at the centre. The gas is energised by the radiation from the star and takes on colours that are determine by its composition, very often the green of triply ionised oxygen. M57, the Ring nebula (NASA/ESA public domain) I tried hard to answer and fulfil the questions and requests from my guests and one of the first queries raised before we left the kitchen, was “Can we see any planets?”. Unfortunately it’s pretty poor times in the UK right now for the top targets and will be for some time. However, the two ice giants are in the southern sky so in theory are visible but crikey they are a long way off. With Olly’s help and whilst the others warmed up in the kitchen we changed to my old Schmidt Cassegrain telescope that has a focal length of 2.3 metres to attempt this feat. This also meant realigning the telescope mount. That took a few minutes but it was then possible to pick out Uranus, which is about 4 Earths wide at a distance of nearly 3 billion miles! It is obviously a disk that has a slight green tinge. We also tried to view Neptune, which is a massive 4.5 billion miles away but the view was slightly obstructed by my roof! Uranus and Earth comparison (NASA public domain). Visitor comments Carole kindly remarked about the group’s experience of the evening and her words are below. “We had been looking forward to this evening ever since we bid for it in the auction. It took a while for us to find a time that was good for everyone and for the skies to be clear and not moonlit. It was well worth the wait and a huge thanks to Chris for offering the event and putting on such an amazing evening. Having only a very limited knowledge of astronomy, it was great to have Chris enthusiastically explaining to us what we were seeing. He has an array of different telescopes and he patiently set them up in his observatory for us to get the best view of the various stars and planets. Seeing the telescopes and learning about how they are controlled to lock onto coordinates in the sky is fascinating in itself. Chris has already described above the range of astronomical bodies we focused on in just a couple of hours. Before the evening I don’t think any of us had heard of Messier’s catalogue! There is just so much to observe and it was a treat to see two remote planets. Neptune was a bit naughty trying to hide behind the house chimney but we just about saw it. We also saw Uranus, which was a bonus. Everything else was good to see and the evening was very enjoyable so we hope to see some more at a future date.”
  39. 4 points
    Ask any astronomer what most frustrating thing about the pursuit is, and they will likely give you an answer along the lines of ‘cloud.’ I always quite liked clouds, especially those fluffy ones like on the title credits of the Simpsons (puts on Nerd Hat, straightens bow tie, clears throat “I think you’ll find those are called Cumulus clouds.” Takes off hat, gets back into cupboard under stairs) so, naturally, when I was warned about what a menace they were, I was sceptical. Let me tell you, a menace they are. This weekend’s viewing was defined by my telescope racing to clear spots to try and pinpoint an object before the cloud closed in. Not very successfully I might add. So what was once my friend as a photography has become my enemy as an astronomer. But then, I will have to wind my neck in and accept that some nights will just go that way. In the grand scheme of things, a clouded off astronomy session is not a big deal, particularly as I have a shameful collection of DVDs of other people doing astronomy for when I can’t. So clouds are truly the enemy of free thinking astronomers everywhere, and I have myself spent more time shaking my fist and cursing at clouds in the sky than actually looking at anything in it. Still, it’s given me scope to be very inventive with my curse words. Perhaps every cloud does indeed have a silver lining.
  40. 4 points
    The pier construction project for my 5 inch refractor is nearing completion. Today, I bolted the oak capping, the mild steel levelling plate and my NEQ6 Pro equatorial mount to the top of the reinforced concrete column. All in all I think the project will have cost me about £120 for materials but I did have some of the stuff I needed already in my shed. The weather, true to form, has suddenly turned grim - grey clouds horizon to horizon. I guess this is my fault. Everything seems to have turned out alright so unless the earth crust folds under the imposed weight I should be imaging Jupiter very soon subject to jet stream and cloud cover. The fabrication-construction stages were as follows: Obtaining via the Internet the laser cut 6mm mild steel disc for making the levelling plate. Drilling it to take the 3 stainless steel threaded studs used to fix the levelling plate to the top of the concrete pier. Drilling it to enable my existing extension pillar/puck to be bolted to it. Cutting and welding reinforcing bar to create a reinforcement cage for the concrete pier. Choosing the best location and marking out for the pier. Drilling my existing concrete paving through into the concrete sub base ( i didn't want to dig the paving up for the pier foundation). Chem fixing shear studs and the bottom of the reinforcement cage into the concrete sub- base. Constructing the timber formwork for the pier. Casting the concrete in two pours. Removing the formwork after 14 days. Painting the levelling plate using three coats of Hammerite. Making the timber pillar capping and eyepiece tray from some surplius oak kitchen worktop. Boltting and levelling the capping, levelling plate and NEQ6Pro to the top of the concrete pier. Now I can turn my shed endeavours towards Spectrometer Mk3.
  41. 4 points
    Last night I took 35 80 second subs using my camera with a 400mm tele lens mounted next to a 70 x700mm scope on my EQ3 mount on an EQ5 tripod. Quick and dirty aligned using the polar scope, no drift align. Over 1 hour 7 minutes, the images offset by a total of 32 pixels vertical, 8 pixels horizontal, but almost all the horizontal drift was on the first two images (presumably taking up the backlash). So the real drift was about 32 pixels or 1 pixel every 2 minutes. Looking at the subs I thought I could spot a few where there was more noticeable movement between subs - then I checked and these 'jumps' were where I had dropped subs because of aeroplane trails, causing nearer to a 2-pixel jump instead of one. There didn't seem to be any of the jumps I would have expected if there was significant periodic error in the worm wheel. What was most striking is that every single sub showed nice round stars - as would be expected if the camera had strayed less than 0.5 pixels either side of the mean position. I won't pretend that these results are good enough for long subs, but they do show that an EQ3 mount properly balanced and aligned with a bit of care on a solid tripod is capable of long enough exposures for imaging DSOs. It also suggests to me that it will be worth me upgrading to autoguiding before upgrading my mount - which is against conventional wisdom. It also lends support to my suspicion that the weakness in the normal EQ3 setup is the aluminium tripod not the mount. Something I want to try is taking long, unguided, wide field exposures. With a 28mm lens the tracking errors should be under a pixel even at 10 minutes exposure. This should be also be a way to see if there is significant periodic error.
  42. 4 points
    I like a bit of recycling and so, after I realised that I had not used my old ETX90 RA for at least two years, I decided to get it out of its fabric carry-case and give it 'the once over'. I have to say that little scope is a robust little beggar and optically as sound as the day my partner Toot purchased it for my fiftieth birthday. The fork mount is definitely passed its sell by date but the OTA is definitely too good to waste sitting on a shelf in a bedroom. So today I decided to remove the OTA from the forks so that I could use the ETX on my recently acquired Star Adventurer equatorial mount or otherwise piggy-back on my 127mm.refractor. Being a bit cautious, I consulted the relevant pages of Mike Weasner's site and after a bit of a rumage around to find the right sized imperial allen key, I threw caution to the wind and set about separating the scope from the forks. Once the four hex screws were removed it only required a bit of brute force to slide the two bits apart. 'Houston we have separation' and the jobs a good un! The next part I really enjoyed, a quick trip to Maplins to buy a flight case to house said OTA. I really like pulling out the precut sections of foam etc. However, I have relunctantly come to the conclusion that I have run out of items of furniture in our sitting room behind which I can hide the now seven flight cases from Toot. I have also covered most of my backyard with sheds and if I put anymore stuff in the loft, I will inadvertently convert my house into a bungalow. I'm really pleased that I shall be using the ETX again. It will be good for imaging brighter comets and white light solar work. Hopefully, I will be able to use it to watch the transit of Mercury. On a more positive note, less cash or space intensive, a piece of transmission diffraction grating film arrived mail order from Israel this morning. So next week on rainy days I will be working on my Mark2 DIY filter or the 'VCS' (aka a very cheap spectrometer). I made the COAA version using an Epson printer to print lines on acetate sheet and this works quite well (image in one of my albums) but number of lines per millimetre limited by the printers operating parameters. I have been reading Jeffrey L Hopkins 'Using Commercial Amateur Astronomical Spectrographs' published by Springer. It is an excellent practical read on spectroscopy particularly suitable for someone like me. I sit firmly on a spectral line somewhere between 'reasonably untechnical' and 'complete numpty'.
  43. 4 points
    I've mentioned a few times that I've recently bought a road bike and have started riding a lot more and I though since I've not got anything astronomical to discuss I would do this instead :) I bought a nice giant defy 0 bike on the cycle to work scheme and spent an extra £200 swapping the brakes, chainset and front mech so it now has a full ultegra groupset.it's perfectly geared for an unfit ex smoker like me with a 50/34 chainset and 11-32 casette and I can get up most hills despite my heart rate touching 190bpm on the long/steep ones.I added a garmin edge 1000 to my ride just over a month ago and have been logging my rides on strava.one particular hill I cycle I have dropped 3 minutes off it in 2 months so the fitness is coming. It's all building up to one event-a 73 mile sportive in october-the wiggle south downs ride.I was originally planning on riding the 42 mile version (there's 3-42/73/100) but my friend graham talked me into the 73.so I talked him into riding it too!!!I've analysed the route and there's one section that could cause problems-a closed road climb up butser hill.this is pretty steep with a 0.3 mile section of 10-18.5% and it's narrow and dirty most if the time.I was pretty sure I could do all the rest of it ok but wasn't sure about this as it was as steep but longer than another climb called crooked walk lane that I had failed on.training needed doing so I've worked my way through the steep roads of portsdown hill near where I live and last week I nailed the dreaded crooked walk lane so I was happy with training.anyway I went out Sunday with a route loaded into my garmin that took me from my house, through some gentle hills and quieter roads and out to another longish hill called old winchester hill.managed this pretty ok and down the other side in preperation to try the butser climb on my sportive route.before the ride I had put both these climbs on the route just to recce them and walk if needed but finding my way at the top of butser hill punching the air with lungs slapping my rib cage the mystic had gone a bit.I'm now looking forward to the event even more now I know I can do the hardest bit and can't wait to do the 100 mile version next year. In fact next year has big plans.I want to do at least 5 or 6 of the wiggle 100 milers and the Hampshire hilly hundred too and also cycle round the isle of wight.I was close to trying the Isle of wight recently but I'm not sure I'm ready yet so want to leave it a bit. I'm already dreaming of a trip to France to do some hills like alp d'huez or mont ventoux or le lacets de montvernier but think I'm a way off that yet. Still happy in my new hobby though. Anyone on strava let me know your name and I will add you :) Clear skies Rich
  44. 4 points
    There are a couple of things I’d better point out about this article. First off, I have no affiliation with Skywatcher or any other astronomy equipment manufacturer or distributor. While I’m doing disclaimers I should probably also say I have no connection to Argos or Ford either. Secondly, I appreciate that I have ignored a huge number of telescopes of various makes, models and technologies. Guilty as charged, but then this is not a particularly serious or comprehensive buying guide by any means. It is difficult to believe but there are people amongst us that will tell you quite seriously that you can’t see any of the planets from earth. Spend £400 on some metal, mirrors and glass however and you can show them things that will quite legally blow their minds. OK, it isn’t as satisfying as zapping them with a cattle prod but it does come a close second. It does seem amazing though that you can see Jupiter with your naked eye but it’s absolutely astonishing when you gaze through a half decent telescope and you can see the cloud bands and if you time it right, the great red spot along with any permutation of the four Galilean moons. If you’re really lucky you’ll notice a small black spot on the face of Jupiter and think it’s something on your lens. When it dawns on you that what you are actually seeing is the shadow of the moon Io cast on the surface of its parent planet you may blink a time or two as you feel your mind and horizons spontaneously expand. This is the reason that perfectly sane, well adjusted people choose to meet up in a field in the middle of winter with odd sized tubes and tripods. It is also the reason the number one top tip for buying a telescope is to get yourself out there with them before you spend any money. Now you may think that spending an evening with astronomers will be a bit like meeting a bunch of Gollum’s in woolly hats, jealously guarding their precious telescopes while muttering to themselves about the duplicity of hobbits. But this couldn’t be further from the truth as astronomers love to show off their equipment and besides, no one wears woolly hats anymore. Spend some time exploring the night sky with a bunch of us and you’ll feel like you’ve been let in on a huge cosmic secret but without the rolled up trousers and special handshake. The other thing it will do of course is make you want some equipment of your own. But what to buy? Let’s get the first big no-no out of the way. DO NOT under any circumstances think “I’ll just buy this telescope from Argos as its got a six hundred times magnification and is only £50”. You could be forgiven for thinking more is better when it comes to magnification but there are limits. In much the same way that you can only zoom into a digital photo so far before things get blurry and pixellated, it is the same with your telescope because the optics are only capable of capturing a certain amount of detail. Now consider the quality of the lenses in a £50 telescope from Argos will be somewhere between jam jar and milk bottle, bumping up the magnification to 600x will achieve nothing but disappointment. So you’re probably thinking OK if it’s not magnification what should I be looking for? Good question, but the problem is buying a telescope is a bit like buying a car. There are many makes and models that are suited to a wide variety of uses with an even wider variety of prices. Therefore the precise make and model you need is very much dependent on what you want to do with it and what you can afford. With a car it’s fairly easy to narrow things down as you’ll be reasonably sure whether you need a little runabout or if you must have something scarlet that will take you everywhere in a blur of scenery. A telescope is trickier because having no experience of one you don’t really know what you want to do with it other than ‘look at planets and stuff’. So where to start? You could buy some binoculars to get you going and this is a very sensible idea. Binoculars are a great introduction to astronomy as they’re relatively cheap, easy to use and there are many guides to things you can see with a pair of 10x50’s. But you want a telescope don’t you. So you will ignore this advice as well as the advice to meet up with actual astronomers because who needs to hear wisdom borne from experience when you have Google and this guide. So skipping past all talk of focal lengths and anything else a bit technical here, are some sweeping generalisations that any idiots guide would be proud of. 1-How big of a telescope should you buy? The answer is size matters with telescopes, especially if you’re interested in seeing the fainter galaxies and nebula so as a general rule bigger is better. But the pro’s and con’s can be summed up thus. Bigger = More expensive = Better views = Less portable. So while a 24” Newtonian will give you stunning views of pretty much anything you point it at, fitting it into your car to take to a field will seem like an exercise from world’s strongest man because that mirror will be very, very heavy. And when I say car, I really mean truck as a 24” reflector has the approximate dimensions of a scud missile. 2-What type of telescope should you buy? Well if we drop back into the car analogy many people buy Fords because they are relatively cheap, well made and do what most people need a car to do with little fuss. To my mind the Ford of the telescope world would be a Skywatcher Newtonian reflector. Sure there are BMW and Audi versions of these scopes and many other makes and models too, but if you don’t know precisely what you want to do with your telescope go with the Ford. The range looks like this. The KA would be a 4.5” tabletop telescope like the Heritage-114p Virtuoso. The Fiesta is the 5.1” Explorer 130P. The Focus would be a 6” telescope such as the Explorer 150P The Mondeo could only be the 8” Explorer 200P One of these will surely fit your budget. 3-What mount should I buy? This is somewhat easier to answer. If you want to do astrophotography you need to buy a motorised equatorial mount and a good one at that (read expensive) nothing less than a HEQ 5 but if you’re serious about it then the NEQ6 seems to be the mount of choice. If you just want to do visual observing then the mount doesn’t really make any difference. Dobsonians are easy to setup and use and don’t cost very much. Equatorial mounts require a bit more setting up and if you take it out to a field you will at some point kneel in a cow pat while attempting to polar align it. An Alt-Az mount is somewhere between the two but it’s all a personal preference really. 4-Do you need GOTO? This subject is covered in more detail in another article but the short answer is if you are a total novice and will mostly be observing alone in your garden then I’d say it’s a definite yes. Many of the objects you’ll want to look at are very faint and easy to miss even when you’re in the right area so if you don’t want assistance from some friendly humans buy the computer. In conclusion then, If the only thing you know about a telescope is that you really, really want one then just say no to Argos and buy one from the Ford (Skywatcher) range. Then take yourself down to an observing night with your local astronomy society and see what you really should have bought.
  45. 4 points
    Here is a picture of Ganymede seen through a 10" scope (NOTE THE PICTURE IS NOT MINE). So here is some evidence that It might be possible... I hope I really will see detail on Ganymede and the other moons. Alas Jupiter is not in the sky so i will have to wait :)
  46. 4 points
    There seems to be a definite consensus in these forums that there is a strong positive correlation between new astronomical purchases and less than ideal weather conditions. I am hereby giving due notice and apologies for my splurging of large chunks of cash and inviting the clouds in. After much deliberation, I have decided to birthday treat myself to a full astronomy kit upgrade from my starter 130EQ. I am now sufficiently hooked and certain that this is not a fleeting affair, so have taken the plunge. My goals involve being able to take images as well as doing some proper astrophysics, so a decent mount was a priority. This ended up a choice between the Celestron AVX and the HEQ5. Both look to be great mounts for the price range I could go to. The AVX also has the bonus of coming with decent and cheap OTA options as well, but the EQMOD factor and my desire to observe as well as image at the same time has led me towards a bit of a Skywatcher love-in: HEQ5 Evostar 80ED Pro Skyliner 250px This gives me the ability to practice tracking, aligning all the other good skills an EQ mount requires, along with PC control and a scope designed for imaging. Once set up with a DSLR and subbing away however, what is one to do with oneself? Why, use a Dob and get observing of course! As a cheeky bonus, I also bought a pair of B&S binoculars, the 8x56 ones on offer at FLO. I must thank them for my avalanche of questions they dutifully and uncomplainingly promptly answered. Again apologies to all, but believe me when I say that if the purchase/weather correlation is accurate, no-one will be more frustrated than me.
  47. 4 points
    Friday night. Had quite a few drinks. Took my dog out just before bedtime and lo and behold. The stars are out. Got the sunlounger lined up at the summer triangle, got Stellarium on my MacBook in night mode, got a rug for my dog, and a blanket for me and with a set of 10x50 binos borrowed from NEAS went to work. Very enjoyable. Reminded myself that I still remembered the star names in Cygnus + the various stars around the triangle and through to Arcturus. Meandered around Hercules and spotted M13. Fuzzy, wobbly, but still great. Realised from Stellarium that there were 2 more Messier objects in this area as well. M29 + M39, both open clusters. Found M39 nice and easily. Nice line of standout stars pointing right at it. Looks good in binoculars, more than just a fuzz. Familiarised myself with that area before hunting for the more elusive M29 which was duly found. I also looked out for the various local nebulas and with some averted vision managed to convince my drunken self that I had found them. I think a second confirmation session is required before I can tick them off when I ever get round to doing proper logging of my sessions, no matter how inebriated. Split Alberio, just and then after some more simple wanderings around Delphinus, called it a night. I do wish the skies were like this more often.
  48. 4 points
    My Quark Chromosphere turned up this morning. Hurrah.
  49. 4 points
    I thoroughly enjoy sketching at the eyepiece when observing. Not only does taking the time to make a sketch encourage the observation of finer details, it serves as an excellent record of one's observations and is of greater use than a textual description. As the recent poor weather continues, I have been going through some recent observations and picked out some highlights below. I well remember recently working my way through the Herschel 400 open clusters in Cassiopeia. As I moved towards M103, I found that I could just fit 4 lovely clusters, each with their own characteristics, into one field of view. The resulting sketch took several hours over a couple of nights to complete and is well worth the additional effort even though it slowed my progress through my observing list. NGC 891 was my nemesis object. I read in awe of people who were picking this out in small scopes and yet I could not see it through my 8.5" newtonian. Yet, after my umpteenth time of searching I finally managed to get it, right at the limit of vision. Now, with some experience I can almost observe it when the conditions allow. Now, if only I could get that dust lane as well!! Finally, I now regularly notice the bright star forming region NGC 604 in the galaxy M33 for example but up until a few years ago, I didn’t even know it was there. I first found this exciting object by observing M33 for an hour. Whilst I could say that I did pick up hints of the spiral arms, it was while making the sketch that I noticed a small, fuzzy patch of nebulosity embedded within the glow of the galaxy. After digging around in various references, I realised that I had made an independent discovery of NGC604, a large star forming region larger than the Orion Nebula and even the Tarantula Nebula, albeit 200 years to claim any rights! I have put some more information to describe my approach to sketching on my website if you are interested.
  50. 4 points
    Measurement of Doubles and a Jovian Moon - Baader Micro Guide Introduction The reason for this rather long blog entry is to highlight what has been possible using simple and relatively inexpensive gear to measure the separation and position angle of a number of double stars and the sizes and distances of various objects within the Solar System. The preliminary goal was fivefold: to further skills in star-hopping and to gain a deeper understanding and appreciation of star magnitude. to garner some experience in measuring double stars as accurately as possible. to work out the sizes and distances of a number of night sky objects. to evaluate the capabilities of the 4” refractor. to pass on information that may be of interest or use to others. The Gear Mounted on an equatorial CG-5, I used a four-inch Tal 100rs f/10, a Celestron x2 Barlow and a Baader Micro Guide. This particular eyepiece is an Orthoscopic Abbe with a focal length of 12.5mm and equipped with a laser-etched reticle and screw on red-light variable illumination system. The multi-function astro-metric eyepiece provides sharp images across the field of view and has a twist up and down focuser which is not for eye-relief but to sharpen the finely etched designs for the observer. When focused at the centre, the edges of the scale do not blur and are crisp throughout but might be difficult to read on occasions due to the illumination system sometimes being uneven. There is no glare, stray light or internal reflection from the illuminator but on tighter doubles with a dimmer secondary component or on faint DSOs, for example, one finds they fade between subtle differences in reticle brightness. Lessening this brightness to capture the dimmer object sometimes makes it complicated to read the 360º protractor scale and I have found that the best remedy on such occasions is to dim in and out and use the eye’s memory to capture the reading. The sharply etched reticle scales include a 360° protractor at the edge of the field of view (4), a number of concentric guiding circles (3), a semicircle (2) and a linear scale across the centre (1). For general beginner’s use, the Micro Guide will be very useful to those who wish to work out seperations and angular distances of binary stars and sizes and distences of Solar phenomena, Lunar features, and other objects found within the Solar System and beyond. Focal Length In measuring a binary star’s separation in something as small as arcseconds, it is important to maximise that separation by using as much of the linear scale as possible. By using a barlow, one effectively increases the telescope’s focal length which in turn ensures not only a greater magnification but also a more accurate measurement along the 60 divisions etched onto the Micro Guide’s 6mm linear scale. This means that if separations or sizes are to be measured evermore accurately with only this eyepiece, different and greater focal lengths will eventually be required. Calibration Before being able to use the Micro Guide it is necessary to calibrate its linear scale, that is, to estimate the number of arcseconds in each division in accordance with the given telescope and if used, the given barlow. If ever the barlow or telescope is changed for another or not used, one must repeat calibration with the new set up. There are a number of ways of going about this and I include two methods, ignoring those given by the instruction manuel. The Split Method Find a known double star and note the number of divisions on the linear scale separating the primary from the secondary. If, for example, Albireo has a separation of 34.7” arcseconds and I see that this separation spans 4.6 divisions on the reticle’s scale, then I conclude that each division is 7.54” arcseconds in length. It is a good idea to measure the chosen double star 30º above the horizon to avoid overt atmospheric disturbance or refraction and to take a good number of measurements of that given star to find the mean average. For this method I chose similar partners in beauty but of various separations none of which were so tight that measurements would be rendered near guesses. StarRho ( ρ)Counted DivisionsScale ConstantAlbireo34.7"4.87.23"Almach9.7"1.37.46"η Cas12"1.77.06"ζ Lyrae43.7"5.97.8"Summing and finding the average I now had a workable scale constant of 7.38" which would remain valid so long as I used the same gear. The Drift Method Again, the drift method is to determine the scale constant – the number of arcseconds per division - but I feel gives a more detailed approach and one less reliant of guessing. However, with that said the final scale constant was very similar to the Split method. Turn off any mount drives and time the passage a given star makes along the length of the linear scale from zero to sixty. The star doesn not have to be a double but will need a stopwatch counting to the 100th of a second. It's a good idea to find a star above 30º declination and not too near the Cestial Pole. You turn the eyepiece until the star drifts exactly along or parallel to the linear scale and as it crosses the zero line start timing until it crosses the sixtieth division. You repeat this process about 20 to 30 times in total over a number of days. To ensure as much accuracy as possible try to measure three different stars over a week and with the various timings for each star, calculate their mean average. The Drift’s Scale Constant You’ll then need to convert these particular results into arcseconds with the following formula: S.C. = 15.0411 (T.avg) cos (dec) / D S.C. – Scale Constant. 15.0411 – Earth’s rotation rate per hour in degrees. T.avg – The given star’s mean average drift time. Cos (dec) – The cosine of the star’s declination / - Divided by D – The number of division on the linear scale And that’s it. The resulting figure will be your scale constant and will remain valid so long as the optical gear you use remains the same. In my own case, I found that the average scale constant was again around 7.5” arcseconds per division. Putting Numbers into Practice Over the following days, I tried to measure a number of double stars in the constellation of Perseus. In particular, doubles that I had never worked with. I chose Eta Persei, Struve 331 and Epsilon Persei as guinea pigs for the experiment. I took a number of measurements for each star and again estimated their average separation. The following highlights the concluding results where Est Rho is my estimation and Rho is the official separation. StarEst Rho ( ρ)Rho ( ρ)Errorη Per28.5"28.3"0.7%Σ 33112.9"12.3"4.8%ε Per8.1"8.7"7.4%As can be seen the margin of percentage error is significant and there is room for improvement. Nevertheless, the results were all within 1” arcsecond of error which accords with the kind of results expected from the Micro Guide. Baader informs the reader that “...such measurements can be estimated to an accuracy of about...2” for a focal length of 2000mm.” Working Out Position Angle I found that working out how to take a binary’s position angle quite complicated but eventually the following procedure was taken. The binary is centred in the eyepiece and aligned in such a manner that both components drift through the bisected middle linear division marked 30 on the Micro Guide. The two stars are allowed to drift toward the etched 180º semi-circle and as the primary crosses the inner 360º protractor scale one reads the given angle. It’s a good idea to take a number of measurements, but better still, place those stars dead centre for a general reading error of about 1º to 2º degrees. Measuring Sizes and Distances To measure size (S), count the number of divisions the given object takes up on the linear scale (sc). Divide this number by your set up’s focal length (fl) which will give you a general image-size (i). Multiply this with the known distance to that object (d). S = d (sc / fl) For example, to work out an estimate of the size of Ganymede, I found that it measured no more than about 0.01mm or 0.02mm on the linear scale: a mere dot on the etched reticle. The mean average of this number was divided by my set up’s focal length, giving me the estimated image-size. Noting that Jupiter was about 4.8 AU from Earth (718,069,776km) and that Ganymede has a average distance of about 1,605,000km from Jupiter, I calculated that Ganymede was around 716,464,776km from Earth. This number was multiplied by the image-size giving me a rough size of Ganymede at around 5,373km in diameter. An error of about 2% or around a 100km out. To calculate distance (d), you divide your focal length (fl) by the image-size (i) and multiply this by the known size (s) of the object. d = s (fl / i) Ganymede’s distance from Earth, I knew its size was about 5,373km (really its 5,268km) and was measured on the scale at about 0.015mm. You then divide the focal length by that image-size and multiply by the size of the object. In my case, I found Ganymede’s distance from Earth was about 716,400,000km. Again, an error margin of around 2%. Conclusion The Baader Micro Guide does not come cheap. In Europe it sells for around €165. In the boxed package you receive instructions (often vague), a decent 12.5mm Abbe Orthoscopic eyepiece with the built in finely etched reticle and a battery operated screw-on illuminator. Most will probably think that such an item is an unnecessary expense to include in their eyepiece collection but to counter this argument there is something rewarding in the challenge of meticuously recording and calculating distances and angles and sizes and separations – even if the experience can sometimes be frustrating and that these numbers have already be worked out for you. I have found the Micro Guide to be a useful resource for not only testing patience and recording skills, or the acuity of vision but also an aid in astronomical study. Like sketching or logging, the astro-metric eyepiece helps increase observing skills for it forces you to take note rather than just casually glancing. Indirectly, it helps increase knowledge about the objects you are looking at, for it is necessary to research such variables as size, distance, separations and position angles and by researching these variables and actively working with them, overtime you are gradually able to estimate such things in the field. Finally, it also acts as an impetus to structure a part of your observing session. After a good month with the eyepiece, working with the Sun and objects of the Solar System, I also feel I have come to appreciate a lot more such diverse factors as the quality of my optics and observing site, the effects of atmospheric seeing, sky glow, astronomical and mathematical data, patience, fatigue, mental disposition, and so on. Such insights will not only deepen your understanding of stargazing but also in coming to understand a little more about yourself – which afterall, must be one of the most important goals set out for us.
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