Planetary Nebula Abell 72
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]
Physical Properties
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. [145]
| 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" |
| Dimensions | 127." (optical) |
| 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 |
| Discoverer | ABELL 1955 |
Finder Chart
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.
Visual Observation
Description pending ...