Coma Cluster
The Coma Cluster (Abell 1656) is a large cluster of galaxies that contains over 1,000 identified galaxies. Along with the Leo Cluster (Abell 1367), it is one of the two major clusters comprising the Coma Supercluster. It is located in and takes its name from the constellation Coma Berenices.
| Coma Cluster | |
|---|---|
A Sloan Digital Sky Survey/Spitzer Space Telescope mosaic of the Coma Cluster in long-wavelength infrared (red), short-wavelength infrared (green), and visible light. The many faint green smudges are dwarf galaxies in the cluster. | |
| Observation data (Epoch J2000) | |
| Constellation(s) | Coma Berenices |
| Right ascension | 12h 59m 48.7s |
| Declination | +27° 58′ 50″ |
| Brightest member | NGC 4874 and NGC 4889 |
| Number of galaxies | > 1000 |
| Richness class | 2 |
| Bautz–Morgan classification | II |
| Velocity dispersion | 1,000 km/s |
| Redshift | 0.0231 (6 925 km/s) |
| Distance | 102.975 Mpc (336 Mly) for h−1 0.705 |
| ICM temperature | 8-9 keV |
| Binding mass | ~7×1014 M☉ |
| X-ray flux | (319.20 ± 2.6%)×10−12 erg s−1 cm−2 (0.1-2.4 keV) |
| Other designations | |
| Abell 1656 | |
The cluster's mean distance from Earth is 99 Mpc (321 million light years). Its ten brightest spiral galaxies have apparent magnitudes of 12–14 that are observable with amateur telescopes larger than 20 cm. The central region is dominated by two supergiant elliptical galaxies: NGC 4874 and NGC 4889. The cluster is within a few degrees of the north galactic pole on the sky. Most of the galaxies that inhabit the central portion of the Coma Cluster are ellipticals. Both dwarf and giant ellipticals are found in abundance in the Coma Cluster.