 | This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (February 2014) |
| Emission nebula | |
|---|---|
| Planetary nebula | |
 Abell 31 as seen from the Mount Lemmon Observatory | |
| Observation data: J2000 epoch | |
| Right ascension | 08h 54m 11.4s |
| Declination | +08° 54′ 30″ |
| Apparent magnitude (V) | 15.5[1] |
| Apparent dimensions (V) | 16.2′[1] |
| Constellation | Cancer |
| Physical characteristics | |
| Radius | 10 ly |
| Notable features | A very large and colorful PN |
| Designations | Sh2-290, PK 219.1+31.2, A 31, ARO 135 |
Abell 31 (also known as Sh2-290 or PK 219+31.1[2]) is an ancient planetary nebula in the constellation of Cancer. It is estimated to be about 2,000 light years away. Although it is one of the largest planetary nebulae in the sky, it is not very bright. The central star of the planetary nebula is a white dwarf with a spectral type of DAO.[3] The white dwarf is the dead remains of a star that existed but had died leaving behind Abell 31 and the white dwarf.[4]
Abell 31 is made mostly of hydrogen and oxygen gas with the red gas signifying hydrogen gas and the blue gas signifying the oxygen gas. The nebula has a blue central region being most of the nebula and a red ring around this blue region. The nebula due to its ancient age has its gas being dispersed into the interstellar medium.[5]
Some of the astronomical objects that exist around this nebula from our perspective include the Beehive Cluster (a cluster of about 1000 stars[6]), IC 523 (a galaxy), NGC 2731 (a spiral galaxy), M 67 star cluster (an old cluster of stars sometimes known as the King cobra cluster[7]) and many more.[8]
- ^ a b "PN A66 31". simbad.cds.unistra.fr. Retrieved 10 November 2024.
- ^ Ford, Dominic. "Abell 31 (Planetary nebula)". In-The-Sky.org. Retrieved 2023-10-27.
- ^ González-Santamaría, I.; Manteiga, M.; Manchado, A.; Ulla, A.; Dafonte, C.; López Varela, P. (2021). "Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity". Astronomy & Astrophysics. 656: A51. arXiv:2109.12114. Bibcode:2021A&A...656A..51G. doi:10.1051/0004-6361/202141916. S2CID 237940344.
- ^ Nina Sen (2012-03-22). "Gift of a Dying Star: Skywatcher Snaps Spectacular Nebula Abell 31 Photo". Space.com. Retrieved 2023-10-27.
- ^ "Abell 31, a planetary nebula in Cancer". Anne's Astronomy News (in Dutch). 2013-05-03. Retrieved 2023-10-27.
- ^ "The Beehive cluster: A swarm of 1,000 stars". earthsky.org. 2023-03-15. Retrieved 2023-10-27.
- ^ admin (2015-07-14). "Messier 67: King Cobra Cluster". Messier Objects. Retrieved 2023-10-27.
- ^ Rojas, Sebastián García. "Planetary nebula Abell 31 - Planetary Nebula in Cancer Constellation". Telescopius. Retrieved 2023-10-27.