#123 - Thursday, January 18, 2018 - Snowed In

After nearly a month of clouds, moon, and bitter cold, I finally made it back out to the observatory!  It has been frigid here lately, but I have acclimatized, so the 20s don't really feel that cold anymore.  I bundled up in my Under Armor base layer, fleece-lined sweat pants, sherpa fleece sweater, coat, fleece-lined hat, gloves, and thermal and wool blend socks tucked into snowboots, and trudged through the snow to the side dome at the observatory where the memorial telescope is I've been using.  The snow was a few inches deep, and someone stole our snow shovel a while back, so I cleared the entrance to the dome with my feet and yanked the swollen wooden door open.  After wrangling with the stiff extension cable that plugs into the main building and successfully opening the dome slit, I got all my gear setup.  I think this was the first time that setup went 100% smoothly - no guiding calibration issues, no hardware communication issues, and the telescope was still in perfect focus from my last trip!  My goal for the night: get green and blue channel images on the Pacman Nebula (NGC 281) so I can finally combine them with the red and luminance ones I took last month to create a color image!

Everything went swimmingly, so I went back inside the main building to the warm room and read a book and scrolled through Facebook, and went out to check on things and rotate the dome about every 40 minutes.  The Pacman Nebula is high and to the north, so I didn't need to rotate the dome as often as I do with something in the south - really only every hour or less, since there is more vertical motion than southward objects (and the slit is vertical).  

After taking 20x300s images on both the green and blue channels, I went home at around 11:45 PM.  I had to be at a middle school science fair I was judging before 8 AM, so I needed to get at least some sleep.  Also, yay for coffee!

The next day, when I copied the images over from my tablet to my desktop, I realized that while I had taken 5-minute subframes that night, my red frames were 10 minutes!  I had forgotten!  I'm told by experienced members of my club that I can just run an auto color-balance routine in Photoshop and it should be fine.  Hopefully there is actually enough light in the subframes to see anything - there already isn't much green or blue in the Pacman Nebula.

I've made some progress on attempting to process the image, but things aren't going so well - color gradients for dayz!  I'm enlisting the help of two of my club's more experienced astrophotographers, and I'll post an updated image here when I get there.  But so far, this is the mess I have created:

Object: NGC 281 Pacman Nebula

Camera: SBIG ST-8300M

Telescope: Vixen NA140ssf

Accessories: L frames: Astronomik CLS filter (2 inches), RGB frames: Astronomik RGB type 2c filters

Mount: Losmandy Gemini II

Guide scope: Celestron 102mm

Guide camera: QHY5

Subframes: 

L: 20x600s (3h20m)

R: 9x600s (1h30m)

G: 20x300s (1h40m)

B: 20x300s (1h40m)
See on AstroBin

I'll keep working on it!  LRGB processing is way harder than processing my DSLR color images!

Once I start getting the process down, I'll write a dedicated post on how to process CCD camera LRGB images.  An exciting part in all this is that this is my "longest" image to date - 8.2 hours total of data!

Next post: #124 - Friday, January 19, 2018 - My Old Friend, DSLR

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