NGC 818
| NGC 818 | |
|---|---|
| File:NGC 818 PanS.jpg NGC 818 imaged by Pan-STARRS | |
| Observation data (J2000 epoch) | |
| Constellation | Andromeda |
| Right ascension | 02h 08m 44.5464s[1] |
| Declination | +38° 46′ 37.596″[1] |
| Redshift | 0.014156±0.0000130[1] |
| Heliocentric radial velocity | 4,244±4 km/s[1] |
| Distance | 168.62 ± 8.37 Mly (51.700 ± 2.565 Mpc)[1] |
| Group or cluster | [CHM2007] LDC 148 |
| Apparent magnitude (V) | 13.20[1] |
| Characteristics | |
| Type | SABc[1] |
| Size | ~171,700 ly (52.64 kpc) (estimated)[1] |
| Apparent size (V) | 3.0′ × 1.3′[1] |
| Other designations | |
| IRAS 02057+3832, 2MASX J02084451+3846381, UGC 1633, MCG +06-05-086, PGC 8185, CGCG 522-116[1] | |
NGC 818 is an intermediate spiral galaxy in the constellation of Andromeda. Its velocity with respect to the cosmic microwave background is 4,010±17 km/s, which corresponds to a Hubble distance of 192.9 ± 13.5 Mly (59.14 ± 4.15 Mpc).[1] Additionally, 14 non-redshift measurements give a closer mean distance of 168.62 ± 8.37 Mly (51.700 ± 2.565 Mpc).[2] It was discovered by German-British astronomer William Herschel on 18 October 1786.[3][4]
NGC 818 has a possible active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.[5][6]
Galaxy group
[edit | edit source]NGC 818 is a member of a galaxy group known as [CHM2007] LDC 148. The other galaxies in the group are NGC 834, NGC 841, NGC 845, UGC 1673, and UGC 1721.[7][8]
Supermassive black hole
[edit | edit source]According to a paper based on measurements of the near-infrared K-band luminosity of the galaxy's bulge, NGC 818 has a supermassive black hole with a mass of 1×107.1M☉ (13 million solar masses).[9]
Supernova
[edit | edit source]One supernova has been observed in NGC 818:
- SN 1992az (Type II, mag. 18) was discovered by Christian Pollas on 27 September 1992.[10][11]
See also
[edit | edit source]References
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External links
[edit | edit source]- Error creating thumbnail: File missing Media related to Lua error in Module:Commons_link at line 62: attempt to index field 'wikibase' (a nil value). at Wikimedia Commons
- NGC 818 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
