G350.1-0.3

G350.1-0.3 is a supernova remnant which is located in the constellation Scorpius. It is in the Milky Way, and possibly associated with a neutron star (XMMU J172054.5-372652) formed in the same supernova explosion. The object was formerly mistakenly classified as a distant galaxy.

G350.1-0.3, a bright radio source in the inner Milky Way, was initially identified by comparing observations from the Molonglo Observatory Synthesis Telescope and Parkes Observatory and classified as a supernova remnant in publications from 1973 and 1975. However, later higher-resolution images in the mid-80s revealed an unexpected irregular morphology that differed substantially from other supernova remnant sources. It was then argued that G350.1-0.3 was a radio galaxy or a galaxy cluster, resulting in a reclassification in which supernova remnant catalogues downgraded the object to "supernova remnant candidate" or dropped it completely; G350.1-0.3 was subsequently "forgotten".