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 ascension02h 28m 36s
Declination-10° 32 20″
Apparent magnitude (B)1202h 28m 36s
Surface brightness23.01 mag/arcsec2
Other designations
IRAS 02261-1045, 2MASX J02283732-1032211, MCG -02-07-013, PGC 009426

NGC 948

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NGC 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

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Two 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

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NGC 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

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References

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  1. ^ "NGC 945 - Galaxy in Cetus | TheSkyLive.com". theskylive.com. Retrieved 2024-04-16.
  2. ^ Ford, Dominic. "NGC945 (Galaxy)". In-The-Sky.org. Retrieved 2024-04-16.
  3. ^ "NGC 948 - Spiral Galaxy in Cetus | TheSkyLive.com". theskylive.com. Retrieved 2024-04-16.
  4. ^ "NGC/IC Project Restoration Efforts". ngcicproject.observers.org. Retrieved 2024-04-16.
  5. ^ "Astrovalleyfield". astrovalleyfield.ca. Retrieved 2024-05-03.
  6. ^ 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.
  7. ^ 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.
  8. ^ "SN 2020obd". Transient Name Server. IAU. Retrieved 5 September 2024.
  9. ^ 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.
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