| astr. |
ultra-compact dwarf galaxy (Ultra-compact dwarf galaxies (UCD) are a class of very compact galaxies with very high stellar densities, discovered[24][25][26] in the 2000s. They are thought to be on the order of 200 light years across, containing about 100 million stars.[27] It is theorised that these are the cores of nucleated dwarf elliptical galaxies that have been stripped of gas and outlying stars by tidal interactions, travelling through the hearts of rich clusters.[28] UCDs have been found in the Virgo Cluster, Fornax Cluster, Abell 1689, and the Coma Cluster, amongst others.  wikipedia.org 'More) |
