NGC 5857
Galaxy in the constellation Boötes
From Wikipedia, the free encyclopedia
NGC 5857 is a barred spiral galaxy in the constellation of Boötes. Its velocity with respect to the cosmic microwave background for is 4,911±12 km/s, which corresponds to a Hubble distance of 236.3 ± 16.5 Mly (72.44 ± 5.07 Mpc).[1] In addition, 20 non-redshift measurements give a distance of 228.85 ± 2.06 Mly (70.167 ± 0.633 Mpc).[2] It was discovered by German-British astronomer William Herschel on 27 April 1788.[3]
| NGC 5857 | |
|---|---|
NGC 5857 imaged by SDSS | |
| Observation data (J2000 epoch) | |
| Constellation | Boötes |
| Right ascension | 15h 07m 27.2818s[1] |
| Declination | +19° 35′ 51.942″[1] |
| Redshift | 0.015834[1] |
| Heliocentric radial velocity | 4,747±2 km/s[1] |
| Distance | 236.3 ± 16.5 Mly (72.44 ± 5.07 Mpc)[1] |
| Group or cluster | NGC 5859 Group (LGG 394) |
| Apparent magnitude (V) | 13.1[1] |
| Characteristics | |
| Type | SB(s)b[1] |
| Size | ~107,700 ly (33.03 kpc) (estimated)[1] |
| Apparent size (V) | 1.2′ × 0.6′[1] |
| Other designations | |
| UGC 9724, MCG +03-39-004, PGC 53995, CGCG 106-005[1] | |
The SIMBAD database lists NGC 5857 as a Seyfert II Galaxy, i.e. it has a quasar-like nucleus with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, the host galaxy is clearly detectable.[4]
NGC 5859 Group
According to A. M. Garcia, NGC 5857 is a member of the NGC 5859 galaxy group (also known as LGG 394). This group has six members, including NGC 5859, UGC 9620, UGC 9622, UGC 9672, and UGC 9777.[5][6]
Abraham Mahtessian mentions that NGC 5857 and NGC 5859 form a pair of galaxies and they are in gravitational interaction.[7]
Supernovae
Two supernovae have been observed in NGC 5857:
- SN 1950H (type unknown, mag. 17.6) was discovered by Fritz Zwicky on 17 March 1950.[8][9]
- SN 1955M (type unknown, mag. 14.5) was discovered by Fritz Zwicky on 14 May 1955.[8][10]
