Many of the brighter galaxies in this cluster, including the giant elliptical galaxy Messier 87, were discovered in the late 1770s and early 1780s and subsequently included in Charles Messier's catalogue of non-cometary fuzzy objects. Described by Messier as nebulae without stars, their true nature was not recognized until the 1920s.
The cluster subtends a maximum arc of approximately 8 degrees centered in the constellation Virgo. Many of the member galaxies of the cluster are visible with a small telescope.
The cluster is a fairly heterogeneous mixture of spirals and ellipticals. As of 2004, it is believed that the spirals of the cluster are distributed in an oblong prolate filament, approximately 4 times as long as wide, stretching along the line of sight from the Milky Way. The elliptical galaxies are more centrally concentrated than the spiral galaxies.
The cluster is an aggregrate of at least three separate subclumps centered on the galaxies M87, M86, and M49. Of the three subclumps, the one centered on M87 is the dominant one, with a mass of approximately 1014 solar masses, which is approximately an order of magnitude larger than the other two subclumps.
The Virgo cluster lies within the Local Supercluster, and its gravitational effects slow down the nearby galaxies. The large mass of the cluster has the effect of slowing down the recession of the Local Group from the cluster by approximately ten percent.
A long, hard look at the Virgo Cluster: new images reveal the stars in a distant galaxy - and heat up a long-simmering debate about the universe's age and size. (includes information on detecting faint galaxies in deep space)
Jul 12, 1991; MIT ASTRONOMER JOHN TONRY THOUGHT he might see something new last February, when he aimed the powerful Canada-Hawaii-France...
Virgo images suggest smaller universe. (observations of a galaxy in the Virgo cluster indicate that objects in the universe may be half as far away as previously thought)
Jun 15, 1991; For the first time, astronomers have distinguished individual stars in a galaxy in the Virgo cluster and measured their distance...