Since I am now waiting for the reprogrammed mount control panel to return I have some time to catch up with some archived imagery.
Once thought to be a supernova remnant, this nebula is now known to be an old planetary nebula. It was discovered by renowned astronomer George Abell in 1955. This is one of the first objects in the Sharpless catalog that I have imaged.
Using Palomar Sky Survey plates as source material, US Naval Observatory astronomer Stewart Sharpless published two catalogs of H II regions. The catalogs also contain some planetary nebulae and supernova remnants. This nebula is one of those and the 274th item in his second catalog.
The nebula is located in the constellation Gemini on the border with Canis Minor. It is estimated to be about 1500 light years distant. Deeper exposures than this show the nebula to have a braided appearance hence the Greek mythology Medusa name reference. The nebula is also cataloged as PK 205+14.1 in the catalogue of galactic planetary nebulae published by Czech astronomers Luboš Perek and Luboš Kohoutek.