| NGC 1643 | |
|---|---|
 NGC 1643 imaged by SDSS | |
| Observation data (J2000 epoch) | |
| Constellation | Eridanus |
| Right ascension | 04h 43m 43.9330s[1] |
| Declination | −05° 19′ 09.562″[1] |
| Redshift | 0.016261±0.00000900[1] |
| Heliocentric radial velocity | 4,875±3 km/s[1] |
| Distance | 232.5 ± 16.3 Mly (71.30 ± 4.99 Mpc)[1] |
| Apparent magnitude (V) | 14[1] |
| Characteristics | |
| Type | SB(r)bc pec[1] |
| Size | ~75,100 ly (23.02 kpc) (estimated)[1] |
| Apparent size (V) | 1.1′ × 1.1′[1] |
| Other designations | |
| IRAS 04412-0524, MCG -01-13-001, PGC 15891[1] | |
NGC 1643 is a peculiar barred spiral galaxy in the constellation of Eridanus. Its velocity with respect to the cosmic microwave background is 4,834±4 km/s, which corresponds to a Hubble distance of 232.5 ± 16.3 Mly (71.30 ± 4.99 Mpc).[1] It was discovered by German-British astronomer William Herschel on 28 November 1786.[2]
Supernovae
[edit]Two supernovae have been observed in NGC 1643:
- SN 1995G (Type IIn, mag. 15.5) was discovered by Robert Evans, J. Shobbrook, and S. Beaman, on 23 February 1995.[3][4]
- SN 1999et (Type II, mag. 17.6) was discovered by E. Cappellaro on 4 November 1999.[5][6]
See also
[edit]References
[edit]- ^ a b c d e f g h i j k "Results for object NGC 1643". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 22 August 2025.
- ^ Seligman, Courtney. "New General Catalogue Objects: NGC 1643". Celestial Atlas. Retrieved 22 August 2025.
- ^ Evans, R. O.; Shobbrook, J.; Beaman, S.; Cass, P. (1 February 1995). "Supernova 1995G in NGC 1643". International Astronomical Union Circular (6138): 2. Bibcode:1995IAUC.6138....2E.
- ^ "SN 1995G". Transient Name Server. IAU. Retrieved 22 August 2025.
- ^ Cappellaro, E. (1 November 1999). "Supernova 1999et in NGC 1643". International Astronomical Union Circular (7304): 1. Bibcode:1999IAUC.7304....1C.
- ^ "SN 1999et". Transient Name Server. IAU. Retrieved 22 August 2025.
External links
[edit]- Media related to NGC 1643 at Wikimedia Commons
- NGC 1643 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
