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AKB

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Everything posted by AKB

  1. That was my thinking, but it seems odd on a plate which is a sky survey. There's actually another one or two on the very left-hand edge halfway down. This image shows it too, although it's unclear to me what the provenance is (obviously POSS-I somehow, but not via the site that I used.) https://www.astronomy-mall.com/Adventures.In.Deep.Space/palpix.htm#pal2
  2. Thanks for that, Mike. Really informative. I must try harder… but that presupposes a certain level of knowledge which I don’t possess! Tony
  3. The start of another month, and another Zoom virtual observing session for the local astro club (Abingdon.) This was the third go at running it this month, the previous Monday and Tuesday being complete washouts. There was much discussion as to whether the rain and clouds would clear in time to start at 20:00, and for some of us, it did. Several other members had widefield scopes with colour cameras and gave us some great views of some favourite nebulas: Monkey Head, Jellyfish, California, Wizard, ... I stuck with the monochrome Hyperstar/Ultrastar as, for me, it works very well in this scenario. For simplicity, and to space out my contributions, I stuck to 20 x 30 second images. A couple of nebulas – to show that they can look good in mono (although, to be fair, they're great in colour.) NGC 1333, the 'Embryo' reflection nebula, in the western part of the Perseus molecular cloud with very active star formation NGC 1579, the 'Northern Triffid', actually an H-II region, again with star formation IC 289 – planetary nebula in Cassiopeia, with some features clearly visible. Also an apparent pair of galaxies on the RHS of the shot, along with a marvellous linear chain of stars blow. NGC 2419 – the 'Intergalactic Wanderer', actually believed to orbit the Milky Way at a distance of ~300,000 LY, taking 3 billion years to do so Documented elsewhere from this evening's haul are: Arp 331 – https://stargazerslounge.com/topic/351721-arp-galaxies/page/6/#comment-4177351 Comets 29P and 2019L3 – https://stargazerslounge.com/topic/384395-three-comets/#comment-4177330 Globular cluster Palomar 2 – https://stargazerslounge.com/topic/387223-auriga-–-palomar-2/#comment-4177323 After the rain, the transparency seemed rather good. It was a great night. Tony
  4. Arp 331, including NGC 380 and friends – too many to count, really. Also in there, I've labelled PGC1999169 and PGC2001155 about 1,600 Mly away and Mag 18. Also, a quasar there too. Tony
  5. AKB

    Three Comets

    Another opportunity to view two of these last night: 29P – in Aurega (I think) with an L-shaped flare perhaps visible from the nucleus 2019L3 – in Lynx, very close to the 'Intergalactic Wanderer' NGC 241 Tony
  6. During last night's virtual observing session(1-Dec-2021) for the local astro club (Abingdon) I was challenged to get the Palomar 2 globular, which I did... Below is a widefield shot from the usual Hyperstar/Ultrastar combination: This was discovered in the National Geographic Society – Palomar Observatory Sky Survey (POSS-I) started in 1948 and finished in 1958, using the 48" Oschin Schmidt telescope. The survey was repeated in the 1980's and 1990's (POSS-II) using better films and an upgraded telescope. The results are available here: https://archive.stsci.edu/cgi-bin/dss_form?target=palomar+2&resolver=SIMBAD I was keen to see how my 10-minute integration with a 9.25" Schmidt (actually stopped down to 8.6") would compare. Here it is, as a negative, with a similar field of view to the red plate images available from POSS-I and POSS-II, which follow (inverted, flipped, and grey-levels adjusted.) How technology has moved on! (I'm also not at the top of a mountain.) Tony PS: Interesting to note that there are a couple of stars to the right of the cluster which appear in POSS-I and not POSS-II or mine. Not sure what these might be?
  7. I’ve had these symptoms a while ago. Quite frustrating… it seemed to be to do with the driver software losing calibration. It eventually settled down, and I can’t really remember doing anything special, although you might choose to change the USB cable, just to be on the safe side. Hoping that recalibrating will sort thing for you. Tony
  8. Have you tried separating and aligning the RGB components with each other, as an early processing step?
  9. Thanks for that… just trying to learn from the experts. My processing skills are almost non-existent, which is why I do EEVA most of the time!
  10. I definitely need some guidance with respect to my use of sharpening and the various filters available. I suppose it depends on what result you're really trying to obtain., and I really like thegentle look that you get, somehow. I presume that doing something like this to it would be going over the top...? Tony
  11. Looks absolutely great to me! Did you do any sharpening on that? Interested to see if there's yet more detail there as signal-to-noise looks very good. Tony
  12. AKB

    Moonlit EEVA

    Thanks for that, Mike. Trouble is, there’s not inconsiderable overlap between a fair number of classifications, so where to post?!
  13. One of the joyous things about EEVA is that a bright moonlit night need not deter you from observing. Nov 21, 94% moon, slightly hazy, windy, early evening, and not very good transparency... not ideal conditions, one would think... ...so for no particularly good reason, other than it wasn't facing directly at the moon, I fancied that I would take a look at NGC 66xx galaxies in Draco. The Jocular observing list, used as a planning tool, is ideal for this sort of spur of the moment whimsy: "I think I'll rank them by size and see how far I can go, and whilst I'm at it, I'll limit my choice to those above 40 degrees of elevation to make sure I get a clear shot at things." NGC 6643 – nice spiral structure visible. Nearby galaxies PGC 2763587 and 2764674 are mag 17.6 and 17.4 repectively. NGC 6690 – the bright star is mag 7.7 and PGC 2736579 is 17.6 NGC 6654 – a lenticular galaxy with an interesting skew between the axis of the brighter central region and the weaker outer one. PGC 61821 is mag 16.7, and outside this view, but just on the edge of the full frame is the star Alahakan at mag 3.5! NGC 6651 – another spiral with nearby star (unlabelled here) HD 171044 of mag 7.3 and PGC 97551 at mag 18.2 One of the slight challenges is the number of very bright stars nearby, but my recent fettling of the C9.25 Hyperstar arrangement (now slightly stopped down to F2.5 and with the USB cable neatly curved over the corrector plate) has reduced spikes and flaring to something close to the minimum possible ( I believe and hope.) Having seen the above, it's time for my evening meal, so what shall I point to nearby that might be fun to let run? How about the Fireworks galaxy? The image below is just 5 minutes worth of the 45 minutes total that it took, and, frankly, I couldn't tell the difference between the images... due, I suppose, to the moon's glow limiting the achievable contrast. So this is NGC 6946 and Arp 29, and in doing a little research whilst writing up this observation, I checked my copy of the The Arp Atlas of Perculiar Galaxies where it's described as "Spiral with one heavy arm." More than that, though, I was shocked and delighted in equal measure to discover that my image compares remarkably favourably with the image there – one of Robert Gendler's taken with a 12.5" RC and 300 minutes of exposure! Just to make a point, I then gave it a whole 10 minutes on the Elephant's Trunk, Sh 2-131, and was amazed at what came out (this is with no filters at all.) All this before 8.30 PM, since I had to go and do the washing up. Hope you enjoy this as much as I did (the EEVA, not the washing up.) Tony
  14. I’ve always had really great service from W&W Astro, here https://dewheater.com
  15. No, no... it was a substantial move from the UK. CT was lovely, certainly nicer than TX where I was for 5 years!
  16. I’m certainly no expert, and I happen to use PixInsight, but there are plenty of others to choose from. The workflow I used was extremely simple, just to give an impression of what’s there. Your basic acquisition seems OK, apart from the back focus to your field flattener, but you know that already. colour calibration background subtraction mask and stretch (including saturation) Mono with filters is mostly just extra hassle to combine them in the first place, so almost everything you see about processing in general should be just as applicable. My biggest concern, and opportunity for improvement, would be in the correct acquisition and application of flats. Having said that, for someone starting out, you seem to be doing exceptionally well (and having a good camera does help.) Tony PS: I used to live in Brookfield CT, near Danbury, and worked in Ridgefield. Beautiful place, especially this time of year.
  17. Just very quickly passing over the data (which has pretty severe background and vignetting, so I don't think flats have worked) ... Tony
  18. @furrysocks I came across this paper independently recently. Thought I would prototype it in Matlab (my tool of choice for playing with signal processing.) Any further experience of this? Interested as a "black box" in EAA processing. Or has anyone else given this a go? Tony
  19. Absolutely love it. For me the size is right (not too many pixels.) Its only slight downside is amp glow, but that calibrates out just fine with darks. Check out my gallery images using it with an Esprit 120ED or a 9.25" Hyperstar.
  20. Welcome back, from someone else near Oxford! 200P still talked about and used here, I think you'll find. For a planetary camera, you'll be amazed by some of the newer CMOS cameras, which can also do the business for DSO. I'm sure several people with more expertise will be along with advice shortly. Abingdon has a thriving astro club if you're interested in meeting with others – and we're actually doing Zoom-based observing evenings for a while (once a month.) Welcome again, Tony
  21. Here's one target on the original list that I forgot to post... ...actually three edge-on (or nearly so) galaxies in Andromeda: NGC 891 NGC 898 PGC2192261
  22. Oooh. Useful. Just given that a try. I'm thinking: 2MASX J03022035+4617511 just from the look of it... http://simbad.u-strasbg.fr/simbad/sim-id?Ident=2MASX+J03022035%2B4617511&
  23. Oh, thanks. Does that mean I'm missing a catalogue in Jocular, or something? How did you do that?
  24. ...speaking of which, do you have any idea what the fuzzy at about 4 o-clock near the edge of this capture might be? Plate solving with the catalogues that I have loaded does not label it... I can't find it in Pretty Deep Maps, either...
  25. Essentially correct. You don't need to synthesize an L file – Jocular will do that internally itself. You can, no doubt, use the Jocular library for debayering, but the simplest approach is to use "super-pixels", which essentially use a 4x4 matrix (typically of RGGB) to generate a single (RGB colour) pixel, thus binning the image x2 at the same time. This is quite effective for modern CMOS OSC which tend to have small pixels and too many of them for Jocular to be entirely comfortable (in terms of operating speed.)
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