A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo.[1]
Observation data (Epoch J2000)
Constellation(s)Leo
Right ascension11h 37m 50.5s[2]
Declination+21° 59′ 06″[2]
Brightest memberNGC 3753[3]
Redshift0.0304[4]
Distance132 Mpc (431 Mly) h−1
67.3[3]
Binding mass(6.1±1.0)×1014 h−1
50.00[4] M☉
X-ray luminosity1041.98 erg·s−1[4]
Other designations
HCG 57
See also: Galaxy group, Galaxy cluster, List of galaxy groups and clusters

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.

See also

References

  1. ^ "Giant Map of the Sky Sets Stage for Ambitious DESI Survey". Retrieved 3 February 2021.
  2. ^ a b Mahdavi, Andisheh; Geller, Margaret J. (2001). "The LX − σ Relation for Galaxies and Clusters of Galaxies". The Astrophysical Journal. 554 (2): L129–L132. arXiv:astro-ph/0105315. Bibcode:2001ApJ...554L.129M. doi:10.1086/321710. S2CID 118106523.
  3. ^ a b Alatalo, K.; et al. (November 2014). "Strong Far-infrared Cooling Lines, Peculiar CO Kinematics, and Possible Star-formation Suppression in Hickson Compact Group 57". The Astrophysical Journal. 795 (2). arXiv:1409.5482. Bibcode:2014ApJ...795..159A. doi:10.1088/0004-637X/795/2/159. 159.
  4. ^ a b c Fukazawa, Yasushi; et al. (August 2002). "Extended Thermal X-Ray Emission from the Spiral-Dominant Group of Galaxies HCG 57". Publications of the Astronomical Society of Japan. 54 (4): 527–532. arXiv:astro-ph/0207011. Bibcode:2002PASJ...54..527F. doi:10.1093/pasj/54.4.527.
  5. ^ "NAME COPELAND SEPTET". Retrieved 12 October 2018.
  6. ^ 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.


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