History

The planetary nebula Abell 71 (PK 85+4.1) was discovered in 1955 by the American astronomer George Ogden Abell on the photo plates of the Palomar Observatory Sky Survey (POSS). In 1955 he published a first list of 13 globular clusters and the positions of 73 planetary nebulae. The PN had the number 58 (A55 58). Stewart Sharpless added the nebula to his catalog of H-II regions as Sh2-116 in 1959. Due to its size and low brightness, it probably did not recognize it as a planetary nebula. In 1966 Abell published a complete list including the size and description of the 86 planetary nebulae discovered on the POSS photo plates. The designation PK 85+4.1 originates from the two Czechoslovak astronomers Luboš Perek and Luboš Kohoutek, who in 1967 compiled a catalog of all the planetary nebulae of the Milky Way known at the time. ^{[331, 332]}