Virgo Cluster

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The Virgo Cluster is a huge collection of galaxies about 53.8 million light-years away in the Virgo constellation. It contains roughly 1,300 to 2,000 member galaxies and sits at the heart of the larger Virgo Supercluster, which also includes our Local Group (the Milky Way). The cluster’s gravity helps shape the motion of nearby galaxies, pulling our Local Group toward it.

Its main members include the brightest galaxy Messier 49 (M49) and the giant elliptical Messier 87 (M87), which anchors the central subcluster known as Virgo A. The cluster spans about 8 degrees of the sky, and with a small telescope you can glimpse several of its galaxies on a clear night.

Virgo is a mixed bag of galaxy types, with many elliptical and lenticular (older, redder) galaxies near the center and more spiral galaxies toward the outskirts. The spirals are spread in an elongated, prolate shape that is wider than it is tall, stretching along our line of sight toward the Milky Way.

The cluster is made up of several subgroups, including Virgo A around M87, Virgo B around M49, and a group around M86, with other smaller clouds that are still being pulled in. These subgroups are merging to form one larger cluster, so Virgo is considered dynamically young.

The total mass of the Virgo Cluster is enormous—about 1,000 trillion solar masses within a few million parsecs of its center. Many of its galaxies move very fast, some up to about 1,600 km/s relative to the cluster’s center.

The cluster’s gravity also slows the recession of the Local Group from it. Its huge mass creates a hot intracluster medium—gas heated to about 30 million kelvin that shines in X-rays. This hot environment can strip gas from galaxies and even host intergalactic stars, some planetary nebulae, globular clusters, and possibly star-forming regions.

Messier 87’s central black hole is a famous feature of the cluster, with the event horizon imaged in 2019. Fainter cluster members are often cataloged by numbers in the Virgo Cluster Catalog.