Eridanus Cluster
| Eridanus Cluster | |
|---|---|
| Observation data (Epoch J2000) | |
| Constellation(s) | Eridanus |
| Right ascension | 03h 28m 13.8s |
| Declination | −20° 44′ 40″ |
| Brightest member | NGC 1232 (B) |
| Number of galaxies | ~200 |
| Velocity dispersion | 261 km/s |
| Redshift | 0.005570 |
| Distance (co-moving) |
23 Mpc (75 Mly) |
| ICM temperature | ~107K (~1 keV) |
| Binding mass | ~1014 M☉ |
| X-ray flux | 0.105 mCrab |
| Other designations | |
| Fornax II Cluster, de Vaucouleurs Group 31 | |
The Eridanus Cluster is a galaxy cluster roughly 23 Mpc (75 Mly) from Earth, containing about 73 main galaxies and about 200 total galaxies. About 30% have Hubble classifications of elliptical or S0 and the remaining 70% are spiral or irregular. These galaxies reside in smaller groups which are all loosely gravitationally bound to each other, suggesting that the system is still condensing from the Hubble flow and may eventually form a cluster of about 1014M☉. A low velocity dispersion compared to that of, for example, the Coma cluster, supports this hypothesis. The Eridanus Cluster is located in the constellation Eridanus near the Fornax Cluster, and is sometimes called the "Fornax II Cluster".
Column 1: Name of the galaxy
Column 2: Right ascension for epoch J2000
Column 3: Declination for epoch J2000
Column 4: Blue apparent magnitude of the galaxy
Column 5: Galaxy type: E=Elliptical; S0=Lenticular; Sa, Sb, Sc, Sd=Spiral (degree of woundedness of spiral arms); SBa, SBb, SBc, SBd=Barred Spiral; SAB= Intermediate Spiral (between barred and unbarred); Sm, SBm, Irr=Irregular; (r),(rs)=Ring Structure
Column 6: Angular diameter of the galaxy (arcminutes)
Column 7: Diameter of the galaxy (thousands of light years)
Column 8: Recessional velocity (km/s) of the galaxy relative to the cosmic microwave background
Coordinates: 
03h 28m 13.8s, −20° 44′ 40″
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