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coatesg last won the day on May 11 2018

coatesg had the most liked content!

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About coatesg

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    Proto Star

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    West Oxfordshire
  1. I think U Leo is a very ambitious project to have a go at for most observers! I might have a go myself at some point with the 14" once the moon is out of the way, but will need to adjust the OAG for it - oh, for a parfocal V and L filter set... Even for me, it'll still need 5min exposures to get anywhere near I should think...
  2. Cheers - The BRATS team (Brazilian Transient Search) did the hard work in discovery - it just happened to be clear at the right time for me
  3. Catchy name Newly discovered, previously unknown dwarf nova (from spectrum by Hiroyuki Maehara (National Astronomical Observatory of Japan) - Atel #13424) - and possibly a WZ Sge type according to discussion on the vsnet-alert mailing list. I got 2 hours worth of data less than 24h after discovery, but was clouded out unfortunately at this point - another couple of hours would have been perfect! It's currently dimmed to mag 15 - I caught it between about 13.95 and 14.05 on evening of 28th Jan (19:36UT). Data (others is clearer...see the AAVSO lightcurves: https://www.aavso.org/LCGv2/) shows double peaked superhumps, amplitude ~0.04mag, period ~0.06d. All with my ST2000XM, home-made 350m Newt, from W Oxon. Exposures were 3 min through a Astrodon V filter.
  4. Through my 14" newt, and using 2min exposures at the start - given the short period, I always find it a tough balance between getting sufficient signal to noise Vs enough cadence to resolve features in the light curve. It looked OK at the start but the SNR rapidly went downhill - I switched to 3 min at the end but the mist had already won by then!
  5. It'd have to be biblical on the Friday to give me chance! Lost count of the Saturdays wasted waiting for umpires to call the thing off (usually after 2-3hrs of being sat around!)
  6. This is ASASSN-20ap - discovered on 17th Jan 2020, it's a new UGSU type dwarf nova in Lynx. Currently at mag 15.05 in V band, this is a time resolved run from the 20th Jan. Conditions started OK, then deteriorated all the time with ever worsening transparency (now quite misty!). I also very quickly imaged the short period HADS star V451 Dra - easier at Vmag 12.45 - 13.05 !!
  7. Hadn't even thought about either to be honest - barely thought beyond Feb at the moment! I'd like to be able to make it along to one - the VSS one sounds interesting, but it's in the cricket season and that's Saturdays tied up for me as I play in the league....
  8. V799 Aug has a really interesting light curve (I've not seen anything quite as similar either) - graph looks great. Sorry to hear about your back troubles - hopefully you're back on the road to good health now! And also proven the benefit of good documentation!
  9. Cheers. Yes nice to get it all running - just about scraped through with the camera too - needed a desiccant bake as it started to frost up at one corner (but not enough to lose the data!)
  10. First time doing any astronomy since November - weather, life, equipment all in the way. But a reasonably productive night. HADS stars NP Lyn and V1425 Tau both observed for the ongoing HADS study (graphs below - all through a Astrodon V filter). Also did a quick shot of U Gem before I then got clouded out after one single 180s image (!) and measured it at V= 13.869 +/- 0.008. Cheers, Graeme NP Lyn: V1425 Tau:
  11. UGC 394 Very nice here! It's only 0.22 arcmin along the major axis... There is some great detail here (edge correction on what is a very fast newt with a huge sensor aside!) I would agree with @vlaiv about the filler exposures for the star cores and galaxy core - the core of M31 is saturated (not a surprise!). Using short exposures and then an HDR combine into a 64bit depth image should sort that, though of course, it doubles the filesize again in doing so... Great shot nevertheless!
  12. I have a double truss mounted on an Equatorial mount (14" f4.53) - I didn't design it to be a serrurier either, but it's fairly well over engineered! I had trouble with the original Orion aluminium tube - it was too thin and flexed at the focuser with the weight of the camera/focuser, and the tube rings were too weak too. Here's the build thread:
  13. Also known as h and χ Persei, the Double Cluster (comprising NGC 869 and NGC 884) is a "line of sight" pairing in the constellation in Perseus, though actually they are only a few hundred light years apart. The clusters have a combined visual magnitude of 3.7 and 3.8 and are visible to the naked eye as a fuzzy patch between Perseus and Cassiopeia. NGC 869 (top) has a mass of 3700 solar masses and NGC 884 weighs in at 2800 solar masses; the total mass for the complex is estimated in excess of 20,000 solar masses when including an extensive halo of stars. Based on their individual stars, the clusters are relatively young, both 12.8 million years old, with the hottest stars having spectral class B0; NGC884 also has 5 prominent red supergiants including variable RS Per (closest to the centre of the lower cluster). North is to the left in this view. Skywatcher Esprit ED80 SBIG STF8300M + Baader filters MI-250 mount RGB (125m:115m:115m - all in 300s subs., with additional 25x15sec in each channel for bright star cores) Taken remotely from E-EYE in Spain: * Image capture: Graeme Coates & Paul Tribe * Processing: Graeme Coates Bonus points for spotting the small fuzz of a galaxy in the field
  14. Finally removed the spiders, cobwebs, etc from my scope at home (and my word, do the mirrors need a clean... I did have to do a quick clean in place as the Daddy Long Legs spiders had almost completely covered the secondary in web!!!!) and took some variable star data. V460 And as below from 83 x 60 sec exposures through a V filter (these to go into the ongoing HADS project I've been contributing to). I tried to also grab a cycle of DW Psc, but kinda failed when I realised I was imaging through fog... (amazed it was hanging on (just) to the guide star TBH!) EDIT: properly reduced with the sequence from the AAVSO.
  15. I haven't dealt with gradients in PS or Gimp in a long time - one way is to make a suitable greyscale gradient across the field using the gradient fill, apply as a mask and then levels to reduce the gradient. Others might have better explanations!
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