Planetary Nebula Abell 33
History
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]
| Designations | PN 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 ± 4.0 km/s |
| Expansion Velocity | 32.0 (O-III) km/s |
| C-Star Designations | AG82 118, CSI -02 -09366, FB 58, UBV 9180 |
| C-Star Magnitude | U: 14.28, B: 15.43, V: 15.50 |
| C-Star Spectral Type | sd Op, O(H) |
| Discoverer | ABELL 1955 |
Finder Chart
The planetary nebula Abell 33 is located in the constellation Hydra near Sextans. On 11 February it is in opposition to the Sun and crosses the meridian at local midnight. The best observation time is January to April.
