Galaxy cluster in the constellation Capricornus
HCG 87 |
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![](//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/HCG_87.png/290px-HCG_87.png) Galaxy Group HCG 87 |
Observation data (Epoch ) |
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Constellation(s) | Capricornus |
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Right ascension | 20h 48m 11.9ss[1] |
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Declination | −19° 50′ 35″[1] |
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Number of galaxies | ~5 |
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Redshift | 8874 km/s[1] |
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Distance | 400 million |
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HCG 87 is a compact group of galaxies listed in the Hickson Compact Group Catalogue. This group is about 400 million light-years away [2] in the constellation Capricornus. The group distinguishes itself as one of the most compact groups of galaxies, hosting two active galactic nuclei and a starburst among its three members, all of which show signs of interaction.[3] This interaction, which astronomers have called visually, and scientifically, intriguing[4] is being examined to understand the influence of active nuclei on star formation histories.
Members
Members of the HCG 87 Name | Type[5] | R.A. (J2000)[5] | Dec. (J2000)[5] | Redshift (km/s)[5] | Apparent Magnitude[5] |
HCG 87a | S0 pec | 20h 48m 15.0s | −19° 50′ 58″ | 8443 ± 14 | 15.3 |
HCG 87b | SA(r)0 pec | 20h 48m 10.9s | −19° 51′ 23″ | 8740 ± 20 | 15.4 |
HCG 87c | Sb | 20h 48m 12.0s | −19° 49′ 56″ | 8914 ± 7 | 16.1 |
HCG 87d | Sd | 20h 48m 12.8s | −19° 50′ 46″ | 10200 ± 160 | 17.8 |
External links
- Astronomy Picture of the Day
- Galaxy Group HCG 87 – 2003 July 31
- HCG 87: A Small Group of Galaxies – 2010 July 6
- Close-ups of HCG 87
- Galactic Clusters
- Studies of Hickson Compact Groups
References
- ^ a b c "NASA/IPAC Extragalactic Database". Results for HCG 87. Retrieved 2006-10-19.
- ^ "This redshift corresponds to a distance of 120Mpc or 400 million light years (using H0 = 75km/s/Mpc and q0 = 0.1). At the distance of the group, this corresponds to a group diameter of 52kpc, i.e., the group is approximately 170,000 light years across". Archived from the original on 19 February 2020.
PS File download need Photoshop or GIMP
- ^ Noll, Keith. 07/1999. "Hubble Heritage observations of Hickson Compact Galaxy Group 87".
- ^ English, J. et al. 05/2000. "A Minuet of Galaxies: Hickson Compact Group 87 as Viewed by the Hubble Space Telescope". American Astronomical Society, 195th AAS Meeting, #136.04; Bulletin of the American Astronomical Society, Vol. 32, p.884.
- ^ a b c d e "NASA/IPAC Extragalactic Database". Results for various galaxies. Retrieved 2006-10-19.
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