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Showing content with the highest reputation on 08/12/17 in all areas

  1. 17 points
    This one has been sitting around for quite a while... usual thing where I only post when it's not been tweaked for a while! This is a 2 pane mosaic with a couple of new things to me..... The FOV is small and so when you look at it in comparison with the complete Heart nebula complex it really puts my differing FOV's into context. I have processed this one differently to my usual as I felt that when I did my more normal colours it looked a little flat. Leaving some green and cyan seemed to give it a depth that was otherwise lost. This is 50 hours worth of total exposure. Details: Mount: mesu 200 Scope: TMB 152/1200 Camera: QSI690 ws-g with 3nm Chroma narrowband filters. Each pane had the following data.... 20x1800s Ha, 15x1800s OIII and 15x1800s SII. It was pre processed, calibrated and also stitched together in APP. You can see a larger version and information about how it fits in with IC1805 here
  2. 16 points
    My youngest decided to take a look through my scope while it was cooling this evening. “My see the stars” were her words! I think she thought it was a frac though!
  3. 14 points
    After a week of cloud, tonight clear skies appeared and I was able to have a play with my new scope and mount. SW London is not exactly the best place to use a scope like this but I had fun anyway. Set up was quick and within about 15 mins the tec was aligned on the panther mount ready for goto and tracking. My sky surfer v finder comfortably cleared the ‘wheel’ handle so that means it will stay in place. First up was M42 and in particular the trapezium. Seeing must have been ok since E and F were obvious. With my oiii filter in place, there were lovely long tendrils of nebula emerging from the ‘mouth’. Sigma orionis was fantastic with all 4 stars very ball like and obvious. Then onto NGC 2169. Lovely 37 with a cheeky double at the top of the 3 (thanks Stu). Auriga clusters of m36, 37 and 38 were nice but I think the poor skies didn’t bring out the stars so they looked a bit sparse. I then followed Nick’s early winter gems suggestions. Ngc2301 was very much like a dragon with wings and a really nice selection of coloured stars. One to revisit again - liked it a lot. Beta monocerotis was a new one for me and a very straight clear split. The tec is clearly well suited to doubles/triples etc. Hind’s crimson star was another new one for me and boy was it crimson - real surprise this one. Again the tec showed the colour and tight star shape very well. Tegmine needed a good level of magnification to split it into 3 - trickier than double double by a margin I would say. Then I had another look at m42 before finishing with the moon. I’m don’t observe the moon very often but with the 4mm DeLite giving 280x it was a delight!! I suffer to some extent with floaters but it’s clear the tec soaks up magnification easier than any other scope I’ve had. In fact I was surprised how often I used the 4mm this evening since I rarely go over 200x. The tec was at ease with this - decent seeing I guess. The panther mount is amazing. Easy to align, holds the tec comfortably and the goto and tracking particularly using sky safari and skyfi are very easy. I could cover a lot if I wanted but could also concentrate on an object for an extended period due to the very accurate tracking. Of this new setup it’s the mount that has made the leap forward in ability compared to my other setups. In respect of the Tec, the build quality is excellent - very close to my AP. The 3.5 inch feathertouch focuser is brilliant, better in my opinion than the AP focuser. The feathertouch makes fine focusing such an easy task. So I think I’ve found my dream visual setup. I’m looking forward to try my night vision monoculars with it (still waiting for the adapters from the US) The only slight negative is the weight and length. The 12kg weight means I have to be very careful when mounting it particularly as the mounting point is quite high on the panther. Also the extra length does mean that the viewing height can change markedly- I’m pleased I got the pier extension for viewing those objects near the zenith (rather than be laying on the ground!) Howver, thsee issues come with all bigger fracs. In summary, a great first light and I’m looking forward to taking it to a dark site to get it to strut it’s stuff more
  4. 11 points
    Another widefield I took on 25th/26th Nov using my Baader modded 350d and Canon 85mm EF f1.8 USM (working at f4.5). This is 21x5min, so 1h45m total taken at ISO400 using an IDAS P2 filter from here in Oxfordshire. I'm sure the region doesn't need too much introduction. To be honest, it needs a lot more exposure, and arguably taking with something more sensitive with less read noise! Being a bit further south would help me too...there was a heavy dose of DBE to sort the gradients out here. Barnard's Loop, the Bogeyman, M42/3, Flame and Horsehead all relatively easy, and the dusty stuff (part of The Orion Molecular Cloud Complex) that extends between them passing by M78 is reasonably obvious, though the fainter stuff is all a bit noisy still. There's also the bluish nebulosity LBN 915 *just* on the limit of visibility to the right of Sh2-278 that extends around the right of eta Orionis. As I said though, it all needs much greater SNR, and less need to resort to MMT for noise reduction... (any more and it started to adversely affect the image). Both images reduced to 2048px width here for convenience. Thanks for looking.
  5. 8 points
    Just as I was going to bed, I spotted that the skies had suddenly cleared. I set up the 80mm APM triplet, with ASI178MM and rattled off 4000 frames. This is the result of stacking 1000 of them and sharpening in ImPPG. Needs to be seen at full resolution.
  6. 7 points
    Hi, Asteroid (3200) Phaethon has been in the news lately. It's a 5 km-wide PHA, the source of the Geminid meteors and currently at its closest for a long time. It passes just 0.069 astronomical units (10.3 million kilometres) from Earth at 23 UT (11pm GMT) on 16 December. Then there’s a 76-year wait when it will attain magnitude +9.4 on 14 December 2093, at 0.0198 astronomical units (2.96 million kilometres or 7.7 lunar distances) from our planet. It's got a highly eccentric orbit with a period of 523½ days that brings it closer to the Sun than any other named asteroid. For ten nights starting 8 December, it is 12th-magnitude or brighter and well placed in the Northern Hemisphere as it speeds up through Auriga, Perseus, Andromeda, Pisces and Pegasus at a rate of up to 15 degrees/day. I had a go at capturing it last night, with intention of producing a light curve to show its rotation. Unfortunately gusty winds and passing clouds messed the imaging up a bit, but I did manage to get some captures of it. It was moving at a rate of 5.5 arcseconds a minute, and its motion was very noticeable in only 30 second exposures. Here's 16 minutes of 30s exposures, stacked in DSS. Field of view about 33' x 24': And here's an animation. 7 frames, each consisting of 5 stacked 30s exposures. It really speeds up over the next few days (from Astronomy Now):
  7. 6 points
    Tonight, three pints down, I came home and the wind had dropped a bit, sky had clear patches, and I had new EP sitting in the kitchen. I received a 16mm 82deg Nirvana in the post yesterday from an SGL member - my first 82deg EP. I was itching to try it out in the 12". After my typical three - Double Cluster, M37 and M42 - I figured I'd try for M33. M31 on the way, never impressed me yet, as if it doesn't really count. The moon was up and bright but further away than last time. I knew, by gross proportions, where to find it. So I red-dotted to somewhere and began a spiral search. It didn't take that long until a patch, in seemingly otherwise empty space, presented itself - most easily discernible while actually moving the scope. I tried flicking my eyes around, looking elsewhere, tried the other eye, closed both eyes for a moment and tried to surprise it, etc... but I figure both the beer and the moon were against me. I had no doubts at all that I was looking directly towards M33, confirmed since by the adjacent star patterns. It's not that long since I imaged M33 in my 4", since sold - that was my first ever self-sight of another galaxy (other than M31) - but tonight, I got my first galactic visual (other than M31). I didn't try any other EP, I only had the 16mm outside with me. No structure, no extent, no core, just a presence, but still a first. I don't know what I've got against M31, but I'll be back to M33 again.
  8. 6 points
    Trying to utilise the dual rig to the full this is 24x300s from 414ex-osc plus 12x180s of LRGB followed by 10x600s of Ha from 428ex-mono. Pre-processed in PI plus initial noise reduction and stretch; colour processed in PS. Would value any comments or suggestions on improving the end result. Thank you for looking.
  9. 6 points
    I shot last night an Oxygen featureless panel around Orion mainly for the stars. However, I didn't immediately take the camera and the lens off so I shot also the moon through the O3 filter (I was too lazy to refocus for another filter). This is at ~300mm focal length with an ASI1600. Not bad for such a short lens.
  10. 5 points
    Some of you already know this, having followed my threads on the indi-forum and maybe the zwo users group. A while ago I started testing INDI on a 64 bit Rock64 sbc, to replace my Raspberry Pi. The advantage of using a Rock64 computer is that it is a faster machine and it has USB3. ZWO recommends using their cameras on USB3 machines to reduce amp-glow. Amp-glow in their cameras is (partially?) caused by the slow read out when using USB2. Installing the indi library and getting that to work wasn't much of an issue, but I never got the zwo efw to work. After some discussions on the zwo forum, the bug was identified (cross compiler problem) and solved. Jasem Mutlaq of INDI updated the library, and now it all works. Here's a write up of how I installed everything: -------------------start of write up------------------------- Rock64 ubuntu installation Installation downloads to my windows machine: download xenial-mate-rock64-0.5.10-118-arm64 from https://github.com/ayufan-rock64/linux-build/releases This is a stable release extracted using 7zip written to sd-card using win32diskimager (Btw, this is not the final release, see below) Booted the Rock64: this starts the mate desktop (default login is rock64/rock64, but yo might want to change the password at least) connected to hdmi, tplink usb device connects to wifi. in the network manager for the wifi network (that's where you've set the SSID, passkey), allow the network (wifi) connection for all users Installation of indi: installed indilib full and kstars bleeding, see the ubuntu instructions on the indilib website. Next is to install the indi web manager: Installed pip: sudo apt-get install python-pip This installed an older version. However, upgrading did install the newest. Tried installing indi web manager, but got a compilation error: Python.h - no such file or directory. Solution: install Python-dev $ sudo apt-get install python-dev // this is for python 2.7 (for Python 3.x use:) $ sudo apt-get install python3-dev 171104: installed latest pre-release 0.6.x in order to get access to usb3 patches EFW doesn't work with rock64. Tried a lot. Among other things, building indi from source. Reinstalled SD card several times, trying several pre-releases. The Ubuntu release I use now is: Ubuntu 16.04.3 LTS (GNU/Linux 4.4.77-rockchip-ayufan-136 aarch64) ... project on hold, waiting for ZWO fix and work getting in the way ... 171208: after communicating with ZWO (zwoug forum) and on the indi forum, the filter wheel issue is solved. It turned out to be a cross compiler bug in the asi driver for the wheel. ZWO issued a fix that was implemented by Jasem Mutlaq of INDI. All I had to do was update and upgrade the system. Now it works fine. -------------------end of write up--------------------------- Image download seems faster than on the Raspberry Pi. So far I've only tested it with a USB2 cable in the USB3 connector (the USB3 cable has a kink). But setting the bandwidth in the indi control panel of Ekos to 100, I seem to get a substantially faster download of captured images to my computer. No first light yet, due to clouds (isn't there a "sudo apt-get upgrade" for that?) For those of you willing to try this, installation should be trouble free if you use Ubuntu and connect to the indi repository. Just install and upgrade should get you a workable solution. And what about the amp-glow? Well, so far the only test I've been able to do is indoors with an uncooled camera, using a USB2 cable in a USB3 port. As I mentioned, I set bandwidth in the indi control panel of the camera to 100, and seem to get a fast download time to my laptop (camera --> usb3-ish --> Rock64 --> wifi --> laptop). But there's still amp-glow. This isn't a magic bullet; all I hope for is an improvement. And even if it doesn't reduce the amp glow, I still can squeeze out a few more exposures per session if download time is shorter. And with short exposures, that makes a difference. Hope this can be of use to someone.
  11. 5 points
    not to bad from the garden shame the houses are in the way orion with the eos 200D and 50mm lens at f7.1 on the star adventurer 32 x 5 minute exposures at iso 6400 stacked in dss and processed in photoshop cs2 total 2 hours 40 minutes thanks for looking
  12. 5 points
    Oh, very well... For those so inclined, this is the Berlebach UNI 29C. I will collect my thoughts while the tears of joy subside.
  13. 4 points
    60mm Lunt Double stacked with 60mm Coronardo and PGR Blackfly cam Best 101 of a 1000 frames A little more detail today as i swapped the b/f over to the old one I also removed the 2nd erf as well. Still having to increase my "usual" exp to double though. Click though for full res
  14. 4 points
    There's a lunar occultation of Regulus around 10.15 - you'll need a clear north east horizon as it will be quite low in the sky. It's been a mix of snow showers and crisp skies here, but could be worth catching, along with some early Geminids. I think the goose down underwear might be required though ! andrew
  15. 4 points
    Stu, yes the bigger exit pupil at high mags was very noticeable imo. Shame there’s no big planets around...oh and I forgot to mention - I split the pup for the first time ?
  16. 4 points
    And there you have the problem. It isn't that cars can't evolve, but that we can't. To fit into that imaginary car, people would need to be shrunk to the size where 1 000 fit into the palm of your hand. The economics and physics of car manufacturing is completely different from electronics. And astro gear manufacturing is completely different still. Plus, as mentioned before, the market is different. A former ceo of IBM once said that the entire computer market was limited to about four units. Boy, was he wrong. As for glass not changing, that's physics. Even the material used for computers hasn't changed. It's still silicon, aluminium and gold, mostly. But unlike electronics, you can't really miniaturise scopes. We want aperture and focal length. Actually, now I come to think of it, a lot has happened. Who would have thought 10 years ago that excellent astro images could be produced by cmos and ordinary lenses. Yet, that's where we're headed with cooled cmos from the likes of zwo, qhy and atik. And computerised goto telescopes are available to the masses, thanks to skywatcher and others. Direct drive, super accurate mounts that don't need guiding are being developed and affordable to more and more people. But again, the market is too small for direct product development on the same scale as for computers and cars. One indicator of this is the lack of large size mono cmos. Since the market is in consumer cameras, there's no incentive for the manufacturers to move from osc to mono.
  17. 4 points
    I was in a state of watching it and not watching it at the same time.
  18. 3 points
    As always this is a wip (work in progress) and is actually a violation of a simple rule a former member on here SteveL gave me when I was starting out with imaging and he was assisting with the processing. He got me to promise to never capture less than an hour on any object. Well, this one breaks that rule (just), sorry... but circumstances in the shape of excessive cumulus clouds keep getting in the way. This is 11x 5 minute exposures of the Rosette Nebula through a little Borg 55FL... one of the reasons I wanted to try a little Borg was for the wide fields one can get.. Unfortunately with this image I've found myself wanting a slightly wider field of view - I didn't know there was so much to capture around the Rosette rather than just the object itself... Anyway, here it is. Very much a WIP and I'll hopefully be adding a lot more data to it weather permitting as I'd like more data to better bring out the fainter nebulosity that extends to the left and lower left in the picture. I really don't want to do a mosaic but I wonder how far those 'plumes' for a lack of a better word go to the left Detaily stuff: 11x 5 minute subs in Ha (Baader 3.5nm enforced filter) Borg 55FL @ f/3.6 with a ZWO ASI1600mm-cooled Captured, guided, controlled through the SkyX, processed in Pixinsight, all on a Mac I've gone heavier on the noise reduction than I'd like but more data will remove the need for that! Please click on the picture for a better, non-jpegerized image! James
  19. 3 points
    Apollo 17 (45 years on) in real time http://apollo17.org/
  20. 3 points
    Here they are on the DIY P-mount. I needed to add an M12 bolt, with two washers and a nut as extra counterweight, but now it moves nicely. Can't wait to get this combo out of the kitchen and under clear skies
  21. 3 points
    Recently got the ES14mm 100°. The televues are great. Once you go green and black you never go back. A big shout out to the Myriad 100°, I don't use it much as I have an F10 SCT, but when I do its great (on brighter objects like the moon, planets > if you can ever see 'em, and brighter planetary nebulae and Globs ), and especially good on my friends 14" Dob. Clear skies!
  22. 3 points
    I would add make it a frac, she obviously knows which is the right end to look through.. Alan
  23. 3 points
    Jim A is pretty good and programmes like this were made as primers for the Open University I think so they're a bit above the Brian Cox level. I sometimes wonder whether it is more confusing to use analogies to try and explain things like quantum mechanics than it would be to actually teach people some physics. I discussed the programme afterwards with my OH, who is not daft by any means, but she doesn't have a scientific background. She found the analogies too muddled and convoluted. So I explained about photons and polarisation and the supposition of states and the creation of entanglement in simple terms and she said yes I get all that, why didn't Jim A say that instead of muddling it up with coins and gloves and whatnot.
  24. 3 points
    Good review Gavin. Awesome set up. Another newbie for the UK TTS160 club here : just received mine. I can't wait to give mine its maiden run.....possibly tonight if the snow keeps off !
  25. 3 points
    @Paul73I have tried to convince him of the advantages of brute aperture, but he won’t relent.... quality rather than quantity! Peter
  26. 3 points
    A very nice compliments card. Oh, yes - there were some other bits in the box as well...
  27. 3 points
    Make sure you don't confuse white light with Ha observing. Absolutely no need for a front filter and a Herschel wedge. They both do a job of reducing the intensity of light and heat reaching the eyepiece and your eye. Doubling up on the reduction would, I imagine, result in a view so dim it would not be worthwhile. Not sure why such worry about techniques and equipment which is well established and used safely by so many people without any problems. I use a Herschel Wedge with an expensive refractor (Takahashi FC-100DC) and have never had any problems at all. If the Wedge falls off the only risk is a hot leg!
  28. 3 points
    My set up from the SGL camp this year. Managed to get some very nice views while there, next step is to invest in a new camera and start experimenting with Astrophotography
  29. 3 points
    Just after midnight there were some decent size holes in the cloud so I setup the Mak. There was no time to wait for cooling so I should have used the refractor really but it was too windy for a long tube. The clouds were moving fast but I did manage to grab 20 frames and stack them. The IQ was terrible due to the warm scope no doubt but here's the result.
  30. 3 points
    Ok. I can only speak for the 450D though. Turn the camera on. Press menu (top left) Along the top row there is seven icons. Arrow across to the sixth icon (yellowish) using the butttons that surround SET. Click on Custom Functions (top one) Press SET Again using the left and right buttons scroll through untill you see long exposure noise reduction. TURN OFF. Scroll to next which is High ISO noise reduction. TURN OFF. I,m not saying this is correct, but it is what i have done, need to to test out. Cheers. Mick.
  31. 3 points
    "If I hadn't watched that program, then it wouldn't have existed" and I'd get one hour of my life back lol
  32. 3 points
    ...and you solved it how? This is a forum to exchange ideas, woes and possible solutions. There might be other members wanting to know. Christer
  33. 2 points
    Flaming stars nebula to Jellyfish nebula. canon eos 200D 50mm f1.8 at f7.1 star adventurer mount on a manfrotto travel tripod 18 x 180 second at iso 12800 total eposure time 54 minutes will add more if we get some clear skies dso's in this are NGC1857 - NGC1892 - NGC1896 - NGC1907 - NC1931 - NGC1985 - NGC1996 - NGC1988 - NGC2028 - NGC2029 NGC2158 - NGC2174 - NGC2163 - NGC2175 - NGC2195. IC2120 - IC405 - IC410 - IC417 - IC419 - IC425 - IC436 - IC439 - IC443 - IC444 - IC2144 - IC2156 IC2157 - IC2159 - IC2162. M1 - M35 - M36 - M37 - M38. enjoy spotting them i know i did lol with the help of all sky plate solver thanks for looking.
  34. 2 points
    Fantastic photo. I did my bit for starting ‘em young. My niece Jessica who’s 11 now delivered a part of my talk with me at our AS meeting this evening. She was a little star!
  35. 2 points
    I just had the combo outside, and the results are very pleasing indeed. Stars are sharp out to at least 85-90% of the radius of the FOV . Views of the Pleiades and other open clusters were superb, what with the added stability from the mount. Really pleased with the views
  36. 2 points
    Buy her a scope. She is after all going out with you, even if it is freezing cold.
  37. 2 points
    @Ags The issue is that the OTA length can affect the amount of vibrations. The longer an OTA is, the more a mount and mount head should be. Your 150PDS is 5.6kg (OTA only) and I assume it has a f.l. of 750mm. From the way I see an OTA of 750mm can sit on a Report, but this only for portable use. Adding eyepieces, finder, and a mount, you can easily reach 10kg. I believe the Report will cope with this as this weight is within its specs, but you might be limited to low power observations. Let's say that you are observing a planet. Would you enjoy vibrations lasting 2-4 seconds every time you focus? Or small vibrations every time the wind blows a bit? Anyway, I think it would be useful for you to contact Berlebach directly and ask whether the Report model you have in mind can cope with your 150PDS. I'm sure they will give you a fair answer. Some answers to your questions. The way that I do for observing is to calculate the maximum payload (including the mount head) I am going to put on the tripod. Then I discard every tripod with a maximum payload less than twice that weight. After this, I consider other factors such as: - Is this tripod meant to be easily portable? (define what easily portable.. by bike? by car? to plane? to be moved around in the garden?...) - How to observe: standing or sitting? If standing, the legs will likely be extended. This means that a more robust tripod might be needed. - Central column? If so, this can decrease the sturdiness of the tripod. Therefore, more payload capacity might be necessary. - is it meant for low power or general observing? For general observing (including high power) a sturdier tripod might be needed. - how long is the OTA? Longer => sturdier tripod (and mount head) - I would ask people with your OTA and figure out what sort of tripod do they generally use, what are their experiences, etc. In the end it is a trade off and tends to go as more portable, less sturdy, more vibrations. Hope this helps
  38. 2 points
    Whoops sorry the 11th, you are correct about the brightness it will certainly not feel as bright as at night time. Not sure about filters I have never tried to be honest. I think I read somewhere about using a single Polarizing filter for daylight observing, I guess a bit of trial and error is going to be called for.
  39. 2 points
    I've got the Uni28 on my future list Glad you're using plenty of senses to enjoy your new mount
  40. 2 points
    Good report and well done on M33 - it can be pretty ellusive until you realise that you are looking right at it ! Your scope should also show you NGC 604 which is a small fuzzy spot next to a brightish star to one side of M33 (though the star is much closer to us). NGC 604 is actually a massive nebula within the galaxy M33 - if it was in our galaxy it would far outshine and be much larger than the Orion Nebula. Here is a little piece on observing it and a couple more of M33's wonders: http://www.skyandtelescope.com/observing/triple-treasure-in-triangulums-pinwheel110320150311/
  41. 2 points
    I thought it was a reasonable program about the old quantum theory. It needs updating getting away from the old debates and looking at things like QED and environmental decoherence. Then he need not have got into the issue of "it's only there when looked at". The decoherence time for macroscopic object is <<10^-10s just from the cosmic microwave background alone. Quite simply the moon is alway there as the universe keeps interacting with it. Regards Andrew
  42. 2 points
    I had a final run on the monopod, while the scope was grabbing lunar data. Although they handle just as well as the Helios Apollo 15x70 binoculars (unsurprising, as they have roughly the same weight and magnification) , they really benefit from being on a monopod. I will test it on a P-mount later. I might even be able to have a shoot-out between the Helios Apollo 15x70, Opticron 16x80 Observation, and Helios LightQuest 16x80, should clear skies come this way
  43. 2 points
    A decent 8 - 24mm Zoom eyepiece is a very good thing to invest in. Not only for your omn eyes, but for outreach work in your local park(s), schools, etc. And for kids - as kids (including the one in all of us) will be delighted for "Skydiving on the Moon!" Viewing colourful double-stars is a great nighttime adventure - watching the two colours split wider and wider in the eyepiece as you add more magnification is a treat - for adults and the young ones. Albireo is a show-stopper! Something that's also a very good choice to bring with, if possible, is a good adjustable observing-chair. It's best to have your audience relaxed and comfortable at the eyepiece. This is especially true for kids' whose legs are shorter and often have to stretch upwards and uncomfortably while trying to see the through the eyepiece. Adults too. Being a teacher is fun! Dave Albireo
  44. 2 points
    Its probably a really good time to check the 2nd hand market at the moment, Solar activity is very quite presently. The Coronado PST is an excellent scope, I picked my old one at this time of the year for a very good price. I still think they are much easier to get used to using than the Lunt 50mm.
  45. 2 points
    Copernicus and Eratosthenes The chart above may be considered one of the most important diagrams of lunar science. This graph is the basis for estimating the ages of the parts of the Moon where we do not have physical samples. In the Y-axis of the graph is represented the number N of impact craters in areas where the Apollo and Luna probes collected samples. In the laboratory the ages of these samples were determined and these data are shown on the X axis. The units for the X axis are easy to understand, the age of formation of rocks in giga years, ie, billions of years. Y-axis units represent the cumulative number of craters equal to or greater than 1 km in diameter per square kilometer. Remote sensing scientists use the best images of the Moon to count the number of primary impact craters in areas centered on the locations where the Apollo and Luna mission samples were collected. Normally this crater count covers areas of hundreds of square kilometers in order to ensure statistical significance for the value of N. This graph has been used for a few decades but, for example, Copernicus crater data did not fit with it , there appear to be also many subsequent craters comparing to the assumed age of 0.8 Ga based on the dates made on the Apollo 12 samples than may be a Copernicus radius. But now Harry Heisinger and his colleagues used high-resolution images of the LRO probe to retell the craters that formed on top of Copernicus and its ejected material, determining an N-value that exactly matches what was predicted. The other red markings show that the new N-values determined for Tycho and the Apollo 16 North Ray Crater crater confirm previous estimates. The power of this chart is that you can count craters for many areas of geological interest on the Moon and extend a horizontal line from the calculated values of N on the Y axis to the right until you intercept the curve. Arriving at the bend and down to the X axis you then have the estimated age based on the counts of calibrated craters. Scientists from the Kaguya mission used this technique when they determined that there were lavas with age of 1.2 Ga in the Oceanus Procellarum. This figure is also a story of the bombardment that the Moon suffered, with the tail of the growth being responsible for the steep fall in the value of N to around 3.5 Ga. Nobody knows exactly why the rate of crater formation has stabilized with only a small decrease from 3.5 to 1 Ga, or why it has since plunged. But there are considerable uncertainties in this curve, the lunar samples were dated to determine the ages for Nectaris, Copernicus and Tycho, but there is no clear evidence that the samples actually came from these features. Source: LPOD / Cienctec Adaptation: Avani Soares
  46. 2 points
    Having been brought up to believe that you never view the sun through an optical instrument, at first I was a little sceptical about using anything other than full aperture front end solar filters. Having owned and used a Lunt 1.25" Herschel Wedge for a couple of years now I'm much more comfortable about putting my eye to the eyepiece. I use the wedge with my 100mm, 102mm and 120mm refractors including at outreach events and it works very well. I've very recently acquired a Lunt LS50 H-alpha scope (single stacked) and I'm intending to do more Ha observing next year with this. The initial couple of sessions that I've had with it have been pretty impressive but I'll need to wait and see how deep my interest is in Ha observing before I invest in double stacking it. The prospect of sitting in the sun feeling warm while doing astronomy is getting more appealing as I get older !
  47. 2 points
    If they are still sticky then maybe get the back under there to hold the rubber in place? Just make sure they are flat!
  48. 2 points
    Download the "Virtual Moon Atlas". You can look at the Moon in any orientation and print your own maps to more or less any size you like. Its freeware and very good!
  49. 2 points
    I believe this thread has info regarding Gina's ST80 narrowband imaging results. As others have said just standard RGB filters would still leave you dealing with the spread of focus within each colour frequency band so the results would likely still be mixed. Using narrowband OIII, Ha as Gina did would be much more successful, but I guess you could also get tighter bandwidth colour filters if you really wanted to do RGB?
  50. 2 points
    Some lovely images coming through as well, keep up the good work everyone. Here's my contribution from last night, only managed just under an hour before the clouds rolled in, which was frustrating since it was guiding nice and there wasn't any dew. M1 Crab Nebula, 5x10mins Ha subs using my Quattro 200CF & Atik 314L+
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