Virgo Cluster

A vast and complex cluster of galaxies centred on a point some sixty-five million light years from our own Milky Way Galaxy. It occupies the northern parts of Virgo and the southern parts of Coma Berenices, straddling the border between the two constellations and covering an area of some 120 square degrees. It is easily located to the east of Leo, occupying a region of the sky that lies close 'behind' the seated Lion.

The Virgo Cluster is far more dense than our own Local Cluster; the exact number of members it contains is uncertain, but there are at least 1,500 and perhaps as many as 2,000 separate galaxies of various types within the cluster. It lies at the centre of an even larger group, the Virgo Supercluster, of which the Local Group of galaxies, including the Milky Way, is an outlying member.

The most massive of the galaxies making up the Virgo Cluster is Virgo A or M87, a huge Elliptical Galaxy at the centre of the group. Despite its size, this is not the brightest of the objects in the cluster; that is Virgo B or M49, another Elliptical Galaxy that lies some four million light years closer to the Milky Way than Virgo A. This area is rich with other galaxies, including many from Messier's catalogue. As well as M49 and M87, these include M58, M59, M60, M61, M84, M85, M86, M88, M89, M90, M91, M98, M99 and M100.

The arrangement of galaxies within the cluster is not random; rather they are organised into smaller groupings of which the most prominent are designated Virgo A (organised around the Virgo A galaxy) and Virgo B (around M49). One particularly clear feature of the cluster is a string of galaxies near its centre known as Markarian's Chain, running across the border between Virgo and Coma Berenices.