This is a three-image mosaic of the California Nebula (also known as NGC 1499 and Sh2-220), an emission nebula named for its resemblance to the outline of California. It's large (almost 2.5° long) but extremely faint. It's illuminated by the ~4 magnitude blue giant star Menkib (seen in the lower center of the photograph).
Also appeared at http://www.astronomy.com/photos/picture-of-day December 18, 2014
Technical Information
Date: November, 2014
Location: Green Valley, Arizona
Telescope: Takahashi FSQ-106EDX
Camera: SBIG STT-8300M
Filters: Astrodon Gen 2
Mount: AstroPhysics 1200
Exposure: HaRGB = 9:3:3:3 hours, all unbinned
Software: Acquisition: Maxim DL 5, TheSkyX, Pinpoint, CCD Commander
Processing: CCDStack, PhotoShop CS6 with various plugins
California Nebula (NGC 1499)