Planetary Nebula Abell 24

Abell 24 (PK 217+14.1)
Abell 24 (PK 217+14.1): Planetary nebula in Canis Major; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 60+3*30 min LRGB; Bernese Highlands; © 2011 Radek Chromik


The planetary nebula Abell 24 (PK 217+14.1) was discovered in 1955 by the American astronomer George Ogden Abell on the photo plates of the «Palomar Observatory Sky Survey» (POSS). This survey was exposed on photographic plates with the 48 inch Oschin Schmidt Telescope on Mount Palomar in Southern California. In 1966 he published a second list of a total of 86 planetary nebulae discovered on the POSS photo plates. Most of the 86 PNs discovered on the POSS photo plates are large and have one low surface brightness, which suggests an advanced age of their developmental stage. [331, 332]

Abell 24
Abell 24: Image by VLT of ESO [412]

Physical Properties

The white dwarf star in the center of the nebula has about 0.7 solar masses, a surface temperature of 137,000 K and an evolutionary age of about 11'000 years. The nebula began to form around 20'000 years ago. [411] Distances range from 530 pc to 700 pc. Apparent Magnitudes: B 16.97 mag, V 17.18 mag. [145]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
DesignationsPN G217.1+14.7: A 24, PK 217+14.1, A55 17, ARO 134, VV' 73
Right Ascension (J2000.0)7h 51m 39s
Declination (J2000.0)3° 00' 27"
Dimensions 355." (optical), 296." (radio)
Radial Velocity+12.7 km/s ± 4.0 km/s
Expansion Velocity 14.0 km/s (O-III)
C-Star DesignationsAG82 93, CSI +03 -07491, UBV 7572
C-Star Magnitude15.82 mag (U filter), 16.97 mag (B filter), 17.18 mag (V filter)
DiscovererABELL 1955

Finder Chart

The planetary nebula Abell 24 (PK 217+14.1) is located in the constellation Canis Minor (Lesser Dog). It lies south of the two 6 mag stars HR 3050 and BC Canis Minoris and forms an isosceles triangle with them. The best observation time is November to April.

Chart Abell 24
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]


141Strasbourg-ESO Catalogue of Galactic Planetary Nebulae; A. Acker, F. Ochsenbein, B. Stenholm, R. Tylenda, J. Marcout, C. Schohn; European Southern Observatory; ISBN 3-923524-41-2 (1992); (2021-02-18)
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
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
411«Properties of central stars of planetary nebulae with distances in Gaia DR2» I. González-Santamaría, M. Manteiga, A. Manchado, A. Ulla and C. Dafonte; A&A Volume 630, October 2019; DOI:10.1051/0004-6361/201936162
412Red and Long Dead; (2021-07-26)