With spring coming to an end, I am coming out of hibernation. I went with an easy first target - the pinwheel galaxy aka M101 in the Big Dipper. I had previously shot this with my 200 mm telephoto lens a couple of years ago, and I though that my upgrades since then would do this object far more justice. M101 is ~21 million lightyears away from us. Many background galaxies are visible in this shot and I encourage you to zoom in.
Date: May 11, 2013
Time: 10:00 pm - 11:30 am
Camera: SBIG STF-8300M
CCD Temperature: -10 C
Optics: Takahashi Sky 90 II @ 406 mm fl (f/4.5)
Filter: Astronomik L
Light frames: 16x5 min
Dark frames: none
Flat frames: 19
Guiding: Orion SSAG @ Orion finder (~162 mm)
Mount: Losmandy GM-8
Processing: Stacking in DeepSkyStacker, Curves and Levels PSCS6, GradientXTerminator.
The mount performed far better than I have ever seen - 0.07 pixel rms error on the guide scope which means <0.5 arcsecond error. Focusing was done with a Bahtinov mask and it rocked!