The Pleiades aka the Seven Sisters, &Messier 45, is an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance of about 444 light years, it is among the nearest star clusters to Earth. It is the nearest Messier object to Earth, and is the most obvious cluster to the naked eye in the night sky. It also houses the reflection nebula NGC 1432, an HII region.
With over 1000 minutes of integration this is a rather large (or deep) RGB dataset. Processing however is difficult, due to the very prominent stars and diffraction patterns, and the absence of area without nebulosity (preventing the calibration of gradient removal).