Planetary Nebula Abell 72
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]
Abell 72 is very large with an angular diameter of a little more than two arc minutes, but has a low surface brightness with 16 magnitudes. This suggests an advanced age. The distance was determined to be 1151 parsecs (around 3700 light years) in 2008. 
|Designations||PN G059.7-18.7: A 72, PK 59-18.1, A55 59, ARO 173, VV' 538|
|Right Ascension (J2000.0)||20h 50m 02s|
|Declination (J2000.0)||+13° 33' 28"|
|Radial Velocity||-58.6 km/s ± 23.0 km/s|
|C-Star Designations||AG82 414, CSI +13 -20477, UBV 18031|
|C-Star Magnitude||14.55 mag (U filter), 15.79 mag (B filter), 16.12 mag (V filter)|
|C-Star Spectral Type||IUE obsns|
The planetary nebula Abell 72 is located in the constellation Delphinus (Dolphin). The best time to observe is May to October, when it is highest at night.
Description pending ...