Abell 21 nick named the Medusa Nebula is a planetary nebula in the constellation Gemini. It is located around 1500 light years from here.
The nebula was created by a low mass star transforming from a red giant to a hot white dwarf star and shedding its outer layers in the process.
Imaged in SHO narrowband and RGB for star color at SRO, California. OTA Planewave CDK 14.
Image Processing: Mike Selby