Emission nebula | |
---|---|
Planetary nebula | |
Observation data: J2000 epoch | |
Right ascension | 16h 27m 33.720s[1] |
Declination | +27° 54′ 33.47″[1] |
Distance | 3800[1] ly |
Apparent magnitude (V) | Integrated: 13.7;[2][3] Central Star: 15.5 ± 0.2[4] |
Apparent dimensions (V) | 155.1″ × 154.5″[4] |
Constellation | Hercules |
Physical characteristics | |
Radius | 1.4 ly |
Notable features | Almost perfectly spherical[2] |
Designations | PN A66 39,[1] PN ARO 180,[1] PK 047+42 1[1] |
Abell 39 (PN A66 39) is a low surface brightness[4] planetary nebula in the constellation of Hercules. It is the 39th entry in George Abell's 1966 Abell Catalog of Planetary Nebulae (and 27th in his 1955 catalog) of 86 old planetary nebulae which either Abell or Albert George Wilson discovered before August 1955 as part of the National Geographic Society - Palomar Observatory Sky Survey.[3][5] It is estimated to be about 3,800 light-years from earth and thus 2,600 light-years above the Galactic plane.[1] It is almost perfectly spherical and also one of the largest known spheres with a radius of about 1.4 light-years.[4][2][1]