Virgo Cluster of Galaxies
Virgo Cluster of Galaxies — This giant agglomeration of galaxies is the nearest big cluster of galaxies, the largest proven structure in our intergalactic neighborhood, and the most remote cosmic objects with a physical connection to our own small group of galaxies, the Local Group, including our Milky Way galaxy.
This structure is another discovery by Charles Messier, who noted behind his entry for M91
The Virgo Cluster is extremely rich in member galaxies, with over 2000 large and small members. While most of them are very small and can only be detected with huge telescopes, there is still a very large number of promising targets for amateur astronomers, even with small telescopes, starting at 2 or 3 inch, or even binoculars; this fact is suggested already by the fact that Messier’s catalog list 16 Virgo cluster members: M49, M58, M59, M60, M61, M84, M85, M86, M87, M88, M89, M90, M91, M98, M99, and M100.
Because of the huge gravity caused by the galaxy cluster’s enormous mass, some of the Virgo Cluster members have been accelerated to high peculiar velocities, with respect to the cluster’s center of mass, at least up to 1,600 km/sec.
As the cluster is receding from us at only 1,100 km/sec, some of its members are moving toward us at considerably high blueshift rates, the highest measured for any extragalactic objects. Others happen to move into the direction away from us, and are thus receding at more than souble the velocity as the cluster.