History

The planetary nebula Abell 72 (PK 59-18.1) 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 59). 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 59-18.1 comes 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]}