CTB1 mislabeled Abell 85

This is a faint supernova remnant in Cassiopeia widely mislabeled Abell 85 (which is actually a galaxy cluster in Cetus)

In 1955 Wilson and Abell discovered what looked like a planetary nebulae in Cassiopeia and cataloged it as the 72nd object in their table of planetary nebulae. Eleven years later the catalog was renumbered in a second paper by Abell and this nebula became Abell 85.

However, Wilson and Bolton found an unidentified radio source at the same location in 1971 and cataloged it as CTB1. A decade later the connection was made that so-called Abell 72/85 was actually a visual part of supernova remnant radio source CTB1.

So the SNR nebula was removed from the Abell catalog of galaxies and replaced about 50 years ago by a galaxy cluster in Cetus—now the real Abell 85.

To make too fine a point of it, Abell wrote in a 1957 that he preferred galaxy clusters in his catalog to be identified with ACO not Abell. So, really, galaxy cluster Abell 85 should be ACO 85...but only SIMBAD seems to recognize it as such.