HCG 87

HCG 87
Galaxy Group HCG 87
Observation data (Epoch )
Constellation(s)	Capricornus
Right ascension	20^h 48^m 11.9s^s[1]
Declination	−19° 50′ 35″[1]
Number of galaxies	~5
Redshift	8874 km/s[1]
Distance	400 million

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	20^h 48^m 15.0^s	−19° 50′ 58″	8443 ± 14	15.3
HCG 87b	SA(r)0 pec	20^h 48^m 10.9^s	−19° 51′ 23″	8740 ± 20	15.4
HCG 87c	Sb	20^h 48^m 12.0^s	−19° 49′ 56″	8914 ± 7	16.1
HCG 87d	Sd	20^h 48^m 12.8^s	−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

1. "NASA/IPAC Extragalactic Database". Results for HCG 87. Retrieved 2006-10-19.
2. "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
3. Noll, Keith. 07/1999. "Hubble Heritage observations of Hickson Compact Galaxy Group 87".
4. 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.
5. "NASA/IPAC Extragalactic Database". Results for various galaxies. Retrieved 2006-10-19.