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It is a premise of the Galilean principle of relativity that every reference frame behaves mechanically like an enclosed compartment at rest. As a consequence of this premise it is presumed to be mechanically impossible to discern the motion of any reference frame by observing experiments conducted within that reference frame. Material objects in flight within an enclosed compartment will manifest a particular velocity that arises from momentum transfer through physical contact with the compartment walls. Objects in flight outside of the compartment will exhibit essentially the same behavior via contact with the external physical structure of the moving compartment. However, a sound wave in flight through an enclosed compartment where the air has no wind currents in it will manifest one particular velocity while a sound wave propagating through the still air outside the compartment will manifest some other velocity — in a moving enclosed compartment the contained air’s velocity is the same as the compartment’s velocity and would add to or subtract from the sound wave’s propagation velocity. There is then a difference in the mechanical behaviors of material objects and sound waves when they are moving through any particular medium based on whether that medium is within or outside of a moving enclosed compartment. Under certain conditions an observer in a stationary or moving reference frame may not have to apply the principle of addition of velocities from the Galilean or Lorentz transformation equations to the propagating sound wave. Not every reference frame is an enclosed compartment.
Igor - it lives.. again.
Apple have just replaced the MBP's complete circuit board for the failed GPU under the GPU repair scheme. Free to me.. but if it hadn't been covered it would have been at least £800. However my battery snuffed it during the time under the desk so that was replaced too. The Apple bods noted my hard drive was also on the way out - I'd known this for a while.. so I've fixed a replacement myself. In short the screen, keyboard, and case are about all that remain of the original MBP...
However I now have a working graphics chip again bring on the deconvolution fun again.... and the laptop that means I can now use the telescope in the garden again for astrophotography!
I'm tempted to switch over to a ODroid based INDI installation, simply because it's less hassle having a completely designated controller. How well Kstars and INDI work.. hmm will have to see.
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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.
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
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 31, M 32, M 110
M 81, M 82
Yesterday I was bitten by kernel update (to 4.10.5) on my main computer (I use Fedora 25). The boot process would at some point just stop, with nothing suspicious in the last visible boot messages; the machine was responsive, though, and Ctrl-Alt-Del reboot was possible. Booting using the previous kernel was fine. After reviewing the boot log (where -1 means second-to-last boot, -0 would be the last (successful) boot etc.):
journalctl -k -b -1
it turned out there was a problem uploading firmware blob to my Radeon R7 370 (I use the standard open-source driver):
kernel: [drm] radeon: 2048M of VRAM memory ready kernel: [drm] radeon: 2048M of GTT memory ready. kernel: [drm] Loading pitcairn Microcode kernel: radeon 0000:01:00.0: Direct firmware load for radeon/si58_mc.bin failed with error -2 kernel: [drm] radeon/PITCAIRN_mc2.bin: 31100 bytes kernel: si_fw: mixing new and old firmware! kernel: [drm:si_init [radeon]] *ERROR* Failed to load firmware! kernel: radeon 0000:01:00.0: Fatal error during GPU init
Indeed, for my particular Radeon model the newer kernel tries to upload si58_mc.bin, but the file was missing.
The solution was to get the file from https://people.freedesktop.org/~agd5f/radeon_ucode/, put it in /usr/lib/firmware/radeon and regenerate initramfs images:
dracut --regenerate-all --force
Well hope tonight is the night ,as last night was spent messing,with the sct 9.25 try in jupiter but shes over the house now and the thermals wee on the wobble ,even with the ir 740 pass filt not much luck.
so back to tonight set the 127mm EDT cf up with the 80mm guide scope will include a few images ,
it sits on a cgem head on a astrotec pier
just have to stick the qhy5 and modded dslr 600d on tonight fore the laptop up phd/ back yard eos and away we go will post my results as and when going to get around 3 hours of data. On some small galaxy
I had just picked up a 'Celestron Neximage 5' and was hoping it would clear enough to give it a run.
I set up the CGEM and put the C9.25 on board. Jupiter was in and out the clouds as I hooked up the Neximage.
About 2 years ago I was imaging with a pocket digital camera (a Pentax Optio E30). I had surprisingly good results from this non astro camera.
But eventually I seemed to hit a barrier on improvements. The images were noisy and I couldn't get past a certain level.
I figured when I upgraded my DSLR to one that shoots video, the better chip would be lower noise and higher quality and would take me to the next level.
Survey says XX.
It just didn't turn out that way. The images seemed to have almost no colour and were not even quite as good as those from the $150 Pentax.
The cost of a real planet camera was out of reach, so I fell away from it. Recently observing Jupiter I decided I needed to try imaging again.
I decided to try a planet camera instead of messing around with not astro cameras. I still can't justify the money for a high end camera, but saw the Celestron Neximage 5 - a 5 MegaPixel Planet Camera. I reasoned if this can improve my imaging over the other cameras, the next step will be a monochrome cooled camera.
I'm not expecting brilliant results, but do hope to see an improvement over previous efforts.
Back to New Year's Eve
I removed the eyepiece and put the Neximage 5 in its place. On the computer I could see Jupiter a s a large cloud, I refocused and it was just a few turns of the stock focuser to bring Jupiter to focus. Jupiter was still facing in and out of the clouds. I hit the record button quick to at least capture a few frames.
I changed the resolution up to 2592 x 1944 and Jupiter looked huge on screen. Over the next two hours I captured about 20 video clips of Jupiter.
I twice put the camera away only to be wowed visually and sparked into taking more video. However, later all the videos turned out to be low resolution.
I had tried many different resolution settings on-screen but they had all come out at low res!
Meanwhile back at the scope, I decided to bring out the new 10" Lightbridge. I recently sold my 6" Explore Scientific Refractor and picked up a Lightbridge.
I used a 5mm 2" Ultima LX eyepiece for 255x on the Lightbridge. The view was excellent, Jupiter was crisp and 5 belts were visible. As far as I could tell there was no GRS or other large features on the nearside of Jupiter. I compared the view in the 10" Lightbridge with the 9.25" SCT. The view looked the same to me, I couldn't really see any difference - I was using 184 x (13mm Ultima 2") in the SCT.
I decided to look for Comet 2012 K5/Linear. I googled the coordinates and punched them into the CGEM Handcontroller. I slewed there and hunted around for a few minutes. Then just below two faint stars there it was - a small but distinct cloud. I observed it for a few minutes before moving back to Jupiter.
I tried an OIII filter in the Lightbride to look at The Orion Nebula. The Trapezium almost disappeared, but the nebula eppeared larger and more extended.
Well hooray! Managed to get a look at Comet PanSTARRS this evening, with 10x50 binoculars, at about 6.45pm - just before the clouds got in the way. Very nice it was too - looked great against the twilight background, with the tail clearly visible and a pretty bright coma.
Glad I caught it this evening, because the weather prospects look rubbish for the next few days.
That's the first comet I've seen since 17P/Holmes a few years ago, and the only naked eye one since Hale-Bopp. It's no HB mind - but pretty awesome all the same.
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There are a number of ways to add media to your posts.
1. Click on the MyMedia button in the tool bar
This will bring up a popout screen showing all the different media types that there are on the left, click on the type (image, album or attachment) and it'll show you the available media in that section.
The files will be listed on the post as code as shown in the next screen grab.
But when you submit the post and view it, the images are shown in differing ways depending on which type you inserted.
Images are shown as thumbnails. Gallery Images and Gallery Albums are links to the image and album directly and will take you away from the thread, attachments are thumbnails that expand within the thread as shown in the image below.
2. Use the Attach Files feature
The second way is to use the attach feature at the bottom left of the (full) reply / post message box. Using this will add the image into the attachments area of the MyMedia method above - so you can re-use attachments again and again if needed.
Clicking on the attach file button brings up the Standard Windows Insert File dialog box, I do not have a Mac so cannot show what that looks like (if someone does have a Mac, they can email me a screen grab I'll add it. Click one or many files and click open. These will be uploaded one at a time and you'll see the status of each upload.
Once the file has been fully uploaded onto SGL, you need to click on the ADD TO POST on the right hand side. The software will add a line of code to the post. You must click on the ADD TO POST or it will not get added. If you forget to click add, edit the post (using the full edit) and add the image from the MyMedia button - as the file will have been added into your attachments folder.
3. Insert an image already on the internet.
Click on the little Picture icon on the toolbar, this will bring up a box where you can paste/type in the URL. There are no controls for the size of the file, and the image will be shown full size in the post entry box, which in one way is quite good - but if it's a big image it could be a pain as well.
4. Youtube videos
You can add a your tube video directly into your post by literally just typing the URL into the entry box.
Paste the URL like this
It will show up in your post like this.
I hope that this is a help.
Source: SGL - How to attach Images.
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Happy days V0.11 is finally available - see post http://stargazerslounge.com/topic/234260-lodestar-live-v011-beta/
Looking forward to seeing how people get on with the new display processing controls!
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Have the Friday booked off from work, so it's a late night one for me. Lots of coffee to keep me warm and alert! A very enjoyable few hours in the garden. Managed to catchable glimpse of the following:
really need a dark sky and a low horizon to get the remainder of my Messiers. Hartland Point perhaps?.
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After a disappointing holiday in Devon from a clear skies point of view (great time otherwise), I returned to Essex last night to be greeted by a few stars in the sky. The view in Devon was North facing, different from my south facing garden, so I took my Dob out the front with its security lights and road junction and went hunting for the objects I had lined up for my holiday. This was to be a Cassiopeia night.
Iota Cas. Found this after a bit of a struggle to even see the fainter end of the W! Once found however, this turned out to be a great test of my eyepiece set. Firstly, all 3 were just visible in the TV Radian 10mm. I tried a 2.25 barlow, but as usual, I struggle with barlows, maybe as I have a single speed focuser, maybe just because I struggle. I also compared the view to the Skywatcher 10mm that came with the scope and happily found the view not as crisp as well as narrower and darker, although still splittable. The barlow was pretty much unusable in this eyepiece.
The Baader Zoom was tried, as I have not had a huge amount of joy with this EP in this scope. This was a happier experiment. The zoom is very useful at finding and then splitting and the 8mm full power (which is actually my highest power at the moment) also made the 3 way split quite easily. The barlow again was a bit of a blurry mess. I need to get some proper high power eyepieces it seems as the barlow approach simply is not working for me. Radian 10mm for the rest of the night.
Another thing I noticed is that I am having balance difficulties with the Dob and think I need some counterweight to help prevent the forward tipping and the extreme tension required to prevent slipping.
Next up was Struve 163 (can you tell where this list comes from!). I had already seen the triangle in my hunt for Iota Cas, so this one was pretty easy. What great colours! The C star was far enough away that it didn't even seem like part of the group. This is a mag 10.7 star, so nice to see how I can push the 10''.
Eta Cas was a nice sight and quite easy to find and it was good to gauge how 13 arc seconds looks like in a 10mm EP. However, I could not find the next one, Burnham 1. Even with a clear guide, I just couldn't make it out and will leave to a night when I have more power and possibly darker skies.
Struve 3053 needed a couple of restarts back to the starting star to get, doing the run from Gamma to Kappa and beyond. What a nice reward though. A littler Albireo, with a lovely and crisp orange and blue combination. From the spacing earlier, this looked a little larger than Eta Cas, and so it proves as this is a 15 arc sec difference, so getting a feel for this. To bring me back to earth, Sigma Cas completely eluded me after, and as the clouds started to roll in, I used my MaxVision 28mm to get a feel for stepping with this low power EP and judging distances between the main Cassiopeia stars (2.5 EP width for the Alpha->Gamma step by the way!).
All in all, a very enjoyable hour or so and great to get some time and experience at the eypiece. I used a chair this time rather than a kneeling mat, and preferred it I think, although doing finder work with a straight through is a neck-cricker...
Source: Cassiopeia Double night
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I originally wrote this one back in May last year and since it is time of the year relevant it make sense to post now. This one has a slightly nostalgic tinge to the usual mix of pop culture references and dubious facts wrapped around a vaguely astronomical theme.
As we enjoy the longer days and the slightly warmer winter weather that here in the British Isles we optimistically call summer, it inevitably signals the end of what many would consider the astronomical observing season. Living so far north on our home world means we are fast approaching that period in our orbit when we don’t experience astronomical darkness and our view of many deep sky objects is denied to us. Oh, I know you can still spot the planets and in particular Saturn becomes visible at a less unsociable hour but many people choose to pack away their telescopes for the summer. Instead we spend our money on holidays in the sun, tasty bedding plants for slugs to consume and the obligatory barbeque whenever the temperature hits the high teens and Sol puts in a brief appearance. The other thing we do of course is look back on the winter recently passed and wonder (as we did last year) why we've invested many hundreds if not thousands of pounds on equipment that we've only managed to use a handful of times in the previous six months.
The weather must surely be the most common frustration amongst the UK’s astronomy enthusiasts. Nothing seems to guarantee cloud like a once in a lifetime solar eclipse or a particularly spectacular meteor shower. Oddly enough given our national preoccupation with the weather it also seems to be the one thing we fail to consider when deciding that astronomy is the hobby for us. Much like we all remember long, golden summers from our youth we also only seem to recall winters being crammed full of cold and frosty clear nights. The reality of course is that for most of the year our seasons are a constantly disappointing temperature variation on a dreary grey theme of cloud and drizzle. Yet in the UK we have an uncanny optimism about the weather that flies in the face of all observable evidence and a lifetime of experience. Every year we imagine that this time we’ll have textbook seasons; a gently warming spring giving way to a glorious summer of warmth and activity before easing into a colourful autumn and a cold winter of frost and snow. For a nation that is so cynical about many things our unreasoned optimism about the weather is difficult to understand. Yet the evidence is everywhere from the sales of convertible cars to the popularity of golf. Let’s face it the only reason they recently put a roof on Wimbledon wasn't because of the weather stopping play but because the tennis was being overshadowed by what was fast becoming Cliff Richard’s annual London gig when it did inevitably rain.
It is no wonder then that there comes a time for every astronomer when they seriously consider selling their equipment to fund a new hobby that doesn't involve a dependency on our unpredictable weather. Arguably the most famous example of this is Brian May who clearly got so fed up with his PHD taking so long to complete due to cloud and rain that he learned to play the guitar and became a rock star instead. There’s a good chance you too may harbour thoughts of musicianship being a more entertaining way to spend hundreds of pounds on equipment. Maybe you can picture yourself at family birthday parties standing on your garage roof playing a Hendrix style version of ‘happy birthday’ on a Stratocaster with a full Marshall stack turned up to 11. The reality of course with this being the UK is it will obviously be raining on any given birthday, particularly if some sort of outdoor activity is planned so fortunately for your neighbours that scenario is unlikely to happen. Not only will the weather put a dent in your rock star dreams but you’ll also quickly discover that your coordination isn't what it was when you were a teenager and more crucially you don’t have the uncounted hours of free time that you actually need to learn how to play a guitar with any degree of competency. Sure when you first buy that old six string you may very well play until your fingers bled but you’ll realise that you should really have learned to play in the summer of ’69 not when you are rapidly approaching that age.
If it’s not music then you may decide that you've always wanted to make things out of wood and your sky at night magazine will be replaced by the screwfix catalogue with its many pages of power tools, laser measuring devices and power tools with integrated laser measuring devices. Your shed/observatory will be transformed into your workshop. The pier will now be home to a vice. The desk where your computer and books once resided will now be decorated with an array of saws and chisels and the walls where your moon posters were once pinned will now be covered in arterial spray because those saws and chisels are really, really sharp.
Once you return from casualty you’ll probably decide that you need a nice, relaxing hobby that doesn’t involve sharp implements or ear splitting, vacuum tube powered amplifiers. Thinking about it you will recall those relaxing evenings spent under lovely, crisp, clear skies that you used to enjoy last winter and wonder why you ever decided to get rid of your telescope. Once you’ve reset your password on stargazers lounge and read a few postings you’ll whip out your credit card and spend a ridiculous amount of money on some new astronomy equipment. You will then spend the next few days filled with the kind of excitement you recall from a childhood Christmas when you were expecting to receive a shiny new bike. And much like that Christmas of long ago you will find the day your parcel of astro kit arrives it is pouring with rain.
Out in garden with scope it was 10.56 pm turned round looked up in east and....saw a massive fire ball coming overhead!! very low in sky, it was green with bits of red coming off it, a huge white tail with bits of blue red spewing off it AWESOME site, i dashed in house for camera but missed it has it disappeared west over the houses.
Feels like an age since I last went out for a proper look (not just out of the window). After recent snow, thaw, and now very strong winds and rain today, I wasn't expecting to be going out tonight but as the skies cleared just as the sun was setting I had a feeling it might be worth my while, and it was.
I went out with the binoculars and SkyScout as there was still a breeze and a few gusts. Very cold, and the wind, although not bitterly cold, just made it that bit colder.
I went through Tonight's Highlights on the SkyScout, listening to the audio descriptions as I went, with binoculars to hand for a closer look.
Orion and the Orion nebula were very clear and nice to see, Betelguise too was looking bright and very red, I managed to find the Andromeda Galaxy, not much more than a faint smudge in the west right now, Castor and Pollux, Taurus, and Sirius too (which I mistook for Saturn to begin with). Jupiter and moons were high up in the sky, close to the Pleiades.
To finish off the evening I wandered up the garden a bit to get a glimpse of the rising moon between some trees, a very nice sight - rather yellow looking and on its side (compared to the usual view, which would be much higher up in the sky).
With the moon rising and the temperature dropping, I declared it a fun evening and time to come inside to get warmed up!
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The summer equinox has passed and people are looking forward to Star Parties. I have never been to one, don't know what to expect, have never met the participants. As a solitary observer tucked away in my small North West garden I have been happy to gaze the night skies alone (Mrs Polar Bear often pops out for high mag views of the Moon and Planets) but otherwise I enjoy my own company and get along very well with myself. So I have taken the plunge and committed to attend CSP9 oop North in Cumbria. Watching the CSP9 thread develop I noticed comforting words such as friendly, whisky, bacon butties, and with a host called delilahtwinkle what could go wrong?
Being a tent snob, and loving Glamping my 'usual' nights out are spent in a Cabanon that is the size of a Jovian Moon and takes 2 people an hour to set up. Not ideal, so ebay to the rescue and luckily a smaller Cabanon (think Europa vs Ganymede comparison) was found just up the road from me. Sleeping will be the usual twin air bed and duvets, a single burner will suffice for snacks, unsure as to whether to take the BBQ and the fold away hanging wardrobes !
So camping equipment sorted, onto the scope. Easy decision as I only own one (this week) so the C8 will be coming. Do you put the scopes away each day? unsure, so I found a new moped cover on the local car boot for £3.00 that will do the trick of protecting it. Red light etiquette is an unknown to me, I always observe at home amongst the fairy lights strewn around the garden. As a smoker I worry about lighters, do they affect dark adapted vision? Can I open my car door or do I need to shield the interior lights if I do? So much to learn regarding Star Party etiquette.
I am really looking forward to it, and to meeting up with like minded individuals (whisky drinkers) :wink:
Hi, out last night for a few hours quite cool but clear sky's around 9 pm till 10.30 pm, never seen so many stars in Cygnus!! here in the city, i was most impressed!! did try the camera on the dob but failed miserably, even found the Globular cluster in Hercules which has eluded me for some time!! with the help of Andriod sky map held on the eyepiece, and it points telling you where to go!! cheaper than a go to!! LOL was disappointed!! just a gray smudge!! nothing like the pictures i have seen. mind you Andromeda was the same just a gray smudge. UP this morning 4.30 am to 5.30, wow so clear, out with the evostar, Venus, our crescent moon, Jupiter, Orion you could actually see the nebular with the unaided eye thats a first been in the city. Pleiades was... jaw dropping!! i have not seen it this good for ages!! Jupiter was very bright, had to filter it a bit to see bands better, Then loads dirty black clouds rolled in at start of dawn, ah well! crawled back to bed!! quite pleased with my self.
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A few weeks ago I saw Saturn for the very first time, it blew me away. The sight was just fantastic, its such a beautiful planet. I couldn't believe my eyes at how much detail I could see, the rings were so clear.
I managed to take a photo through the lens with my iPhone.
If you haven't already I really recommend buying a telescope, the views of the night sky never disappoint.
I've had the AR152 up for sale since I got the C9.25 reasoning that The C9.25 should be able to do everything the Refractor can do and with more aperture.
But I never had the chance to put them head to head. The SCT can operate at F/10 with a focal length of 2350 mm - a nice long focal length for planets.
With the reducer lens it can operate at F/6.3 an effective focal length of 1480 mm - getting down to reasonably low power for wide field cruising.
I had over spent the scope budget last year and so decided to liquidate the Refractor - despite it not really having a good chance to prove itself.
Previously the AR152 outgunned my Astro-Tech AT8in - an 8" Imaging Newtonian - on a Jupiter shadow transit.
Although the Astro-Tech has an oversized secondary mirror I still thought the 8" of aperture would over rule the 6" Achromat.
But not so, it was a clear shut out for the refractor. Conditions were a little murky and I could not even detect the shadow with the Newt.
It was clear on the refractor and I switched back and forth twice to make sure conditions hadn't changed.
So, finally tonight - nice warm and dry conditions on a weekend night - when does that ever happen?
I started with the SCT on the CGEM mount. I aligned and looked at the Ring Nebula. The Moon was about 3/4 phase so the sky was a murky light grey.
The Ring didn't look good and I decided not to use it for comparison. I slewed over to M27 and even in the light sky it was easily visible.
I inserted my new Celestron UHC filter in the 2" diagonal and it did improve the image quite noticeably.
I soaked in the view with a 22mm Ultima LX eyepiece (67x). Then I set up the AR152 on the Alt Az - T-Mount.
I eyeballed where the SCT was pointing and just tried to angle the Refractor in the same position. It was mounted very low on the alt az and I had to do some driveway crawling to maneouvre it.
I looked again at M27 through the SCT and memorised the view. Then to the AR152. I moved the whole Eyepiece/Diagonal/Filter combination over to the refractor. I centred M27 and then changed to the Ultima LX 13 mm e.p. (76x) to better match the magnification.
I looked - and Wow! - the refractor put up a view every bit as bright and distinct as the SCT. But that just should not be so - the refractor was giving up 3 1/4
inches of aperture. I looked long and hard and tried to imprint the view.
I moved back to The SCT - switching the optical train over again and then dropping to the 22 mm again.
Nope, the view was not quite as good. It was just less distinct - perhaps less contrasty is the best description.
I took out the UHC filter on The SCT and the view was worse - looking very grey.
Debra arrived home and I asked her to look through both scopes.
She immediately voted for the refractor and said it just looked 'crisper' there.
I started to think of the possible reasons why the SCT was not clouting the Refractor with its greater light grasp and higher resolution.
I figured while using the F/6.3 Reducer, the SCT was using 2 lenses and 3 mirrors before the eyepiece:
the primary mirror
the secondary mirror
the reducer lens
Whereas the refractor was using:
the objective lens
Since each time light is reflected or passes through a lens some if it is lost, it seems likely this must be a big factor?
But still - there's no way my C9.25 should be beat on deep sky by a 'big daft achro' as I have sometimes referred to it.
I've cancelled the sale (not kidding) of the achro pending a planetary shoot-out. There's just no way the Achro can win this one.
The C9.25 is legendary on planets and the Achro is going to have a blizzard of CA pouring out the eyepiece.
I'm thinking Jupiter here ....
But I would have dismissed any chance of it winning on deep sky - so who knows?
I tried the OIII filter but the sky was just too blown out by The Moon do find anything else worth comparing.
I did pull in Epsilon Lyra - The Double Double, and neither scope could cleanly split them - the stars appeared dazzling and a little spikey.
A clear tie on this object.
So there is was last night, gazing up at an amazingly clea sky for the first time since I bought my scope.
The stars were barely even twinkling. I've never seen anything like it for years.
Unfortunately, my scope was 180 miles away.
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I am hoping that soon enough I can have my new 1.25 eyepieces. I love the format I have as well. I just want to be able to use filters as well. I know most of the time I am in light polluted skies and the use of a filter is beneficial even if by a small fraction. I still have yet to discover which telescope for me four millimeter, but that's okay. Right now , I just want to focus on getting more eps and some filters.
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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.
Been busy working on the mechanical side in preparation for its mot and road trip to have the self leveling system fitted , probably in the first week or two of February, a round trip of around 300 miles which should be enough to blow away the cobwebs! As far as mechanical work goes its looking pretty easy thus far, with just a few minor things needing done. Will be replacing the rear discs and pads at the weekend and perhaps skim the fronts I'll see how they perform on a brake test. Also been busy removing the unnecessary oxygen piping and valves, brackets etc and making some headway inside the "observation area", that sounds good doesn't it !
Also been busy removing all the Emergency Ambulance stickers and logos, nasty stuff the damn adhesive... and the disconnecting the blues and twos as well incase temptation gets in the way.
Had a sparky check out some visible wiring and the mains sockets which don't appear to be working, im hoping the auxilliary batteries are just needing charged up as the invertor unit lights up but not got any output.....
No pics on this update bit will take some for next time round.
Thanks for looking and taking an interest.
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So a quick blog today, just to keep things ticking over, and to keep track of my ideas etc – more for me to look back on more than anything else!
Foot is a lot better now – I am getting around ok, and have even started a new fitness ‘regime’!! I have lost 6lbs in one week, by cutting out crisps and flapjacks, and doing 20 minutes of high interval training each morning! Go me!!
I’m still scopeless, and will be until at least Autumn I think. Had my hours knocked down at work from 5 days to 4 days. We can still cope on the reduced income, but it means my scope will be delayed slightly!
I’m not too upset about the lack of OTA right now. Nights are still short, and the weather isn’t exactly brilliant either. It will give me time to finally settle on what I actually want to set – newt or frac!! Its either a 130p-ds or ST102. Both have their pros and cons, and I can’t guess the amount of reviews etc I have read on both scopes!!
In the meantime, I have decided to set myself up with a widefield DSLR rig. Budget is key here! I already have the mount (EQ3-2), DSLR with fast and wide lens, and a means to mount it on the EQ. I just need a polar scope and a motor kit. I am keeping my eyes peeled for them to come up on ABS, AB or on SGL (remember key word – Budget!!). The mount is still due its MOT, which hopefully I will carry out later this month. I want to have it all together for my trip to Pembrokeshire in mid August.
With this set up I am hoping to get my first astrophoto’s of the Milky Way, and perhaps some of the larger constellations. From what I’ve been told here on SGL, 2-4 minute subs should be achievable if PA is good, and LP is not too bad. I will update this blog as each stage is completed, and hopefully with my first photos as well, however they turn out!!
I have been doing a lot of reading up both on SGL, and the wider t’interweb about DSLR widefield, and it’s something I can get into fairly easily, and with minimal outlay. As a keen landscape shooter, I am hoping I can use my current skills to create some pleasing images. We shall see - this blog could well turn into a ‘How To Take AP With No Money’ blog!!
Well, that’s all for this entry – thanks for reading, and sorry it a bit dull this time!! Next entry I am hoping to blog about my mount MOT, along with photos!! Ooooo!!!!