Thursday, May 18, 2017

Comet Johnson C/2015 v2

Monday evening was one of the first clear nights that I was able to actually get out and image some astro-objects.  With comet Johnson high in the eastern sky and the moon out of the way (until at least just after midnight) I setup the Edge11 early to cool down before the image run.

SkyTools recommended over a two hundred 30 sec subs, but I knew that the Hyperstar on the Edge was able to do 120 sec subs without any significant fogging due to light pollution.  So with everything set I started the sequence run of 50 x 120sec subs starting at 10:28 pm, just about 18 minutes after the start of Astro-Dark skies (the time slot recommended by SkyTools).

Of course it wouldn't be a 'Mangieri' night of imaging without some problem cropping up. This time it wasn't the weather, or the mount, or the guiding, but the QHY10 camera.  For some reason it took almost an hour to cool down to the -20C temperature.  It has always completed this cool down in about 10 minutes. Post analysis showed that using the QHYCCD software EzCap (supplied with the camera) completed the cool down at the normal rate. Since I just downloaded and installed the latest release of SGP (my normal imaging software) I suspect that the issue may lie there. Anyway, the evening was a success and I captured 50 nice subs of the comet. The sequence ended at 00:48 am (the extra 40 minutes taken up with downloading each sub to the computer). I tried to use my home-build light box to create a set of flats to improve the post processing, but the light is way too bright to work with the Hyperstar - got to get that fixed.

Since I need some time to process the images, I decided to create a time lapse video of the comet movement among the background stars (accelerated quite a bit!). As the frames progress you can see the ever 'popular' aircraft light streaks! The ugly 'pea soup' sky is because I did not process removal of sky glow (light pollution). It will be removed when I process the still image of the comet.


In the next few days I should be able to post the full color image of Johnson.

No comments:

Post a Comment

More Astrophotos from my Backlog

I just completed the post-processing of a couple of objects from my backlog - one from Feb 6, 2024 (open star cluster M35) and the other the...