This image shows the enormous star cloud NGC 206 within M31, the Andromeda Galaxy. This star cloud contains approximately 300 intensely bright, hot, blue class O and B supergiants spanning a region approximately 4000 light-years in length. NGC 206 is on the edge of other blue star clouds that comprise a major blue spiral arm of M31. A separate, smaller star cloud is visible at lower right. 

Exposures: LRGB=650:240:240:220 minutes=22.5 hours total at f/8

This image was published in the December, 2017 issue of Astronomy magazine.