Planetary Nebula Abell 73

Abell 73
Abell 73: Section of the Sloan Digitized Sky Survey. Here could be your picture. [147]


The planetary nebula Abell 73 (PK 95+7.1) 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 60 (A55 60). In 1966 Abell published a complete list including the size and description of the 86 planetary nebulae discovered on the POSS photo plates. He described its morphological appearance as «C» (a symmetrical ring with bright spots or regions). [331, 332]

The designation PK 95+7.1 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. [146]

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]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
Designations PN G095.2+07.8: A 73, PK 95+07.1, A55 60, ARO 356, VV' 539
Right Ascension (J2000.0) 20h 56m 26s
Declination (J2000.0) +57° 25' 57"
Dimensions 73." (optical)
Expansion Velocity 20. (O-III) 22.5 (N-II) km/s
C-Star Designations AG82 416
C-Star Magnitude B: 21.1
Discoverer ABELL 1955

Finder Chart

The planetary nebula Abell 73 is located in the constellation Cepheus. The best time to observe is May to December, when it is highest at night.

Finder Chart Planetary Nebula Abell 73
Planetary Nebula Abell 73 in constellation Cepheus. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°