Planetary Nebula Abell 2

Abell 2
Abell 2: Planetary nebula in Cassiopeia; 500 mm Cassegrain 3625 mm f/7.2, SBIG STL11K; 320+120+120+120 min LRGB; Bernese Highlands; © 2015 Radek Chromik


The planetary nebula Abell 2 (PK 122-04.1) was discovered in 1955 by the American astronomer George Ogden Abell on the photo plates of the Palomar Observatory Sky Survey (POSS). [331, 332]

Physical Properties

Most of these 86 PNs discovered by Abell on the POSS photo plates are large and have a low surface brightness, which suggests that their stage of development is advanced. The PN is approximately 3.9 kpc away [145]

DesignationsPN G122.1-04.9: A 2, PK 122-04.1, A55 2, ARO 202, VV' 6
Right Ascension (J2000.0)00h 45m 36s
Declination (J2000.0)+57° 57' 24"
Dimensions 36." (optical)
Radial Velocity-41.8 km/s ± 3.1 km/s
Expansion Velocity 34. km/s (O-III)
C-Star DesignationsAG82 7
C-Star Magnitude20.07 mag (B filter)
DiscovererABELL 1955

Finder Chart

The planetary nebula Abell 2 is located in the constellation Cassiopeia, about 1 ° west of the 3.4 mag bright star Achird (η Cassiopeiae). The best observation time is July to January.

Chart Planetary Nebula Abell 2
Planetary Nebula Abell 2 in constellation Cassiopeia. 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]

Visual Observation

Pending ...

More Objects Nearby (±15°)


145SIMBAD astronomical database;
149SkySafari 6 Pro, Simulation Curriculum;
160The STScI Digitized Sky Survey;
331«Globular Clusters and Planetary Nebulae Discovered on the National Geographic Society-Palomar Observatory Sky Survey» Abell, G. O.; Publications of the Astronomical Society of the Pacific, Vol. 67, No. 397, p.258-261, August 1955; DOI:10.1086/126815; Bibcode:1955PASP...67..258A; (2021-05-10)
332«Properties of Some Old Planetary Nebulae» Abell, G. O.; Astrophysical Journal, vol. 144, p.259, April 1966; DOI:10.1086/148602; Bibcode:1966ApJ...144..259A; (2021-05-10)