NGC 945 is a barred spiral galaxy in the constellation Cetus,[1] located south of the celestial equator. It is estimated to be 200 million light-years from the Milky Way, and about 135,000 light-years in diameter.[2] The object was discovered by astronomer William Herschel on November 28, 1785. It is within close proximity to NGC 948, with which it forms a gravitationally bound pair of galaxies. In the same area of the sky there are the galaxies NGC 942, NGC 943, NGC 950, and IC 230.
| NGC 945 | |
|---|---|
 NGC 945 (right) and NGC 948 (left) | |
| Observation data (J2000 epoch) | |
| Right ascension | 02h 28m 36s |
| Declination | -10° 32′ 20″ |
| Apparent magnitude (B) | 1202h 28m 36s |
| Surface brightness | 23.01 mag/arcsec2 |
| Other designations | |
| IRAS 02261-1045, 2MASX J02283732-1032211, MCG -02-07-013, PGC 009426 | |
NGC 948
editNGC 948 is a spiral galaxy located extremely close to NGC 945.[3] Its speed relative to the cosmic microwave background is 4,259 ± 17 km/s,[4] which corresponds to a Hubble distance of 62.8 ± 4.4 Mpc (~205 million ly). NGC 948 was discovered by American astronomer Lewis Swift in 1886. The luminosity class of NGC 948 is III and it has a broad HI line. With a surface brightness equal to 14.17 mag/am2, NGC 948 is classified as a low surface brightness galaxy (LSB).[5]
Supernovae
editTwo supernovae have been observed in NGC 945. SN 1998dt was discovered in NGC 945 on September 1, 1998, by T. Shefler of the University of California at Berkeley[6] as part of the LOSS (Lick Observatory Supernova Search) program at the Lick observatory. This supernova is classified as a type Ib.[7] SN 2020obd (type II, mag. 17.3) was discovered on 6 July 2020.[8]
NGC 945 group
editNGC 945 is the brightest galaxy in a group of at least 7 members that bears its name.[9] The other six galaxies in the NGC 945 group are NGC 948, NGC 950, NGC 977, MCG -2-7-20, MCG -2-7-32 and MCG -2-7-337.[9]
See also
editReferences
edit- ^ "NGC 945 - Galaxy in Cetus | TheSkyLive.com". theskylive.com. Retrieved 2024-04-16.
- ^ Ford, Dominic. "NGC945 (Galaxy)". In-The-Sky.org. Retrieved 2024-04-16.
- ^ "NGC 948 - Spiral Galaxy in Cetus | TheSkyLive.com". theskylive.com. Retrieved 2024-04-16.
- ^ "NGC/IC Project Restoration Efforts". ngcicproject.observers.org. Retrieved 2024-04-16.
- ^ "Astrovalleyfield". astrovalleyfield.ca. Retrieved 2024-05-03.
- ^ Srivastav, S.; Smith, K. W.; McBrien, O.; Smartt, S. J.; Gillanders, J.; Clark, P.; Fulton, M.; O'Neill, D.; Young, D. R.; McCollum, M.; Townsend, A.; Chen, T. W.; Anderson, J.; Denneau, L.; Flewelling, H. (2020-07-01). "ATLAS20say (AT2020obd): discovery of a candidate supernova in NGC 945 (56 Mpc)". Transient Name Server AstroNote. 133: 1. Bibcode:2020TNSAN.133....1S.
- ^ Shefler, T.; Halderson, E.; Modjaz, M.; King, J. Y.; Li, W. D.; Treffers, R. R.; Filippenko, A. V. (1998-09-01). "Supernova 1998dt in NGC 945". International Astronomical Union Circular (7006): 3. Bibcode:1998IAUC.7006....3S. ISSN 0081-0304.
- ^ "SN 2020obd". Transient Name Server. IAU. Retrieved 5 September 2024.
- ^ a b Garcia, A. M. (1993-07-01). "General study of group membership. II. Determination of nearby groups". Astronomy and Astrophysics Supplement Series. 100: 47–90. Bibcode:1993A&AS..100...47G. ISSN 0365-0138.