M101 Pinwheel Galaxy
Roughly the size of our Milky Way galaxy, M101 is 170,000 light years across and 21 million light years from Earth. It has a high population of hydrogen-II regions where stars are believed to be formed. Companion galaxy NGC5477 can be seen at the left edge slightly above center. North is at the bottom.

Scope/Mount: AstroTech AT8RC 8" F8 Ritchey-Chretien with ATFF2 Field Flattener, Celestron CI-700 Mount
Camera: Orion StarShoot Pro V2 one-shot color
Guiding: QHY5L-IIM through Orion Deluxe OAG, PHD guiding software
Exposure: (18) 10 min
Software: Nebulosity, PhotoShop CS2
Comment: 04-18-15, Tierra del Sol, CA. Below average seeing, slight wind.