 A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo.[1] | |
| Observation data (Epoch J2000) | |
|---|---|
| Constellation(s) | Leo |
| Right ascension | 11h 37m 50.5s[2] |
| Declination | +21° 59′ 06″[2] |
| Brightest member | NGC 3753[3] |
| Redshift | 0.0304[4] |
| Distance | 132 Mpc (431 Mly) h−1 67.3[3] |
| Binding mass | (6.1±1.0)×1014 h−1 50.00[4] M☉ |
| X-ray luminosity | 1041.98 erg·s−1[4] |
| Other designations | |
| HCG 57 | |
The Copeland Septet (also Copeland's Septet, Hickson Compact Group 57) is a group of galaxies in the constellation Leo that includes NGC 3748, NGC 3754, NGC 3750, NGC 3751, NGC 3745, NGC 3753 and NGC 3746.[5][6] The group was discovered by British astronomer Ralph Copeland in 1874. The location of Copeland's Septet is right ascension 11h 37m 50s / declination +21° 59′ (2000.0), about three degrees northwest of third magnitude star 93 Leonis.
The redshift of the brightest member, NGC 3753 places Copelands Septet as a part of the Coma Supercluster.[7]
- ^ "Giant Map of the Sky Sets Stage for Ambitious DESI Survey". Retrieved 3 February 2021.
- ^ a b Cite error: The named reference
Mahdavi_Geller_2001was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
Alatalo_et_al_2014was invoked but never defined (see the help page). - ^ a b c Cite error: The named reference
Fukazawa_et_al_2002was invoked but never defined (see the help page). - ^ "NAME COPELAND SEPTET". Retrieved 12 October 2018.
- ^ Bakich, Michael E. (July 10, 2010). 1,001 Celestial Wonders to See Before You Die: The Best Sky Objects for Star Gazers. Springer Science & Business Media. p. 72. ISBN 9781441917775. Retrieved 12 October 2018.
- ^ Jaffe, W.; Gavazzi, G. (1986-02-01). "Radio continuum survey of the coma/A1367 supercluster. II. 1.5 GHz observations of 396 CGCG galaxies". The Astronomical Journal. 91: 204–216. doi:10.1086/114001. ISSN 0004-6256.