Planetary Nebula Abell 33

Abell 33
Abell 33: Planetary nebula in Hydra; Takahashi Mewlon 250 CR, Reducer CR 0.73 (1800mm / f7.25), SBIG ST-8300; 17L x 900sec 1×1, 13R, 8G, 9B 2×2 x 900sec; Bernese Highlands; © 2022 Bernhard Blank, Dragan Vogel


The planetary nebula was discovered by the American astronomer George Ogden Abell on the photo plates of the «Palomar Observatory Sky Survey» (POSS). In his first publication of 1955 he listed the nebula as number 22 (A55 22). [331] In 1966 he published his final list of a total of 86 planetary nebulae discovered on the POSS photo plates. The nebula is there listed as number 33 (A66 33). He described it as a «homogeneous disk» with a «deviation from perfect regularity or symmetry.» [332]

Physical Properties

This planetary nebula shows similar morphology as the Owl Nebula (M 97) but with a visual magnitude of 15.5 it is much darker. Given distances range from 758 to 995 parsec. The bright star in the foreground is HD 83535 with a visual magnitude of 7.21. It is of spectral type A1V and with a distance of 216.6 parsec much closer. [145]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
DesignationsPN G238.0+34.8: A 33, PK 238+34.1, A55 22, ARO 65, VV' 91
Right Ascension (J2000.0)09h 39m 09s
Declination (J2000.0)-02° 48' 33"
Dimensions 270." (optical)
Radial Velocity+60.1 km/s ± 4.0 km/s
Expansion Velocity 32.0 km/s (O-III)
C-Star DesignationsAG82 118, CSI -02 -09366, FB 58, UBV 9180
C-Star Magnitude14.28 mag (U filter), 15.43 mag (B filter), 15.50 mag (V filter)
C-Star Spectral Typesd Op, O(H)
DiscovererABELL 1955

Finder Chart

The planetary nebula Abell 33 is located in the constellation Hydra near Sextans. The best observation time is December through May.

Chart Planetary Nebula Abell 33
Planetary Nebula Abell 33 in constellation Hydra. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±25°)


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