IC 2177: The Seagull Nebula
The thing about the Seattle area and astronomy is that when there is a break in the permaclouds, full moon or not, we take advantage of it by setting up shop. Sadly the last time this happened was about two weeks ago! But luckily that night was a good one for some more Hydrogen Alpha imaging!
Earlier in the day I’d met with a friend at the gym who recently took possession of a beautiful William’s Optics 80mm. (It’s amazing how heavy it is!) While chatting I realized I had mostly gained enough comfort with my new SBIG STL 11002 camera, that perhaps I could pass on my “beginners camera”, the OSC StarShoot Pro v2 to him. All the while examining his scope, and explaining to him the use of his new “hand me down” camera, my scope was pointed right at the beautiful Seagull emission nebula! (Yes, We do have a lot of Seagull’s around Seattle, but they’re usually making a mess near the waterfront and not viewed through telescopes.)
Note: Emission nebula tend to be red (as opposed to bluer reflection nebula), which makes then great Hydrogen Alpha imaging candidates. Located just under 4,000 light years away, the apparent size of this object is nearly 2.5 degrees making it one of the larger slices of winter sky to fill up with a short refractor and a giant sensor!
This image represents 10x 5 minute exposures with the Televue NP101is, Large Field Corrector and SBIG STL 11002. Guiding was done with an external 60mm Stellarvue scope and PHD Guiding. CCD running at -30C; ambient around 0C. As with the Hydrogen Alpha Horsehead Nebula image, this creates a very undersampled image. Using the drizzle stack method really helps improve the overall resolution of the final image and helps round out those stars (instead of leaving them looking like little blocks!) Dithering between frames further helps improve the usefulness of drizzle, but I’ve not yet figured out how to keep CCDSoft and PHDGuiding coordinated. (Nebulosity talks to PHDGuiding, but CCDSoft doesn’t seem to.) Image stacked in Nebulosity, and touched up in CS5. Gradient Xterminator was also used to help fix some of the areas the flats didn’t seem to pull out. What do you think?