See A Galaxy Cluster From Your Backyard

Our own Milky Way and the Andromeda galaxy are the largest of the forty members of the Local Group of galaxies, all held together by mutual gravitational attraction. But the Local Group is puny compared to the massive Virgo Cluster, home to as many as 2,000 galaxies spread across our sky between the stars Denebola in Leo and Vindemiatrix in Virgo. Dozens of these galaxies are visible from your backyard.

• The Virgo cluster is made up spirals galaxies, dwarf ellipticals, and giant ellipticals. The irregularly-shaped cluster is anchored at its core by the immense but featureless elliptical galaxies M84 and M86; the monstrous M87 is not far away.

• The spirals of the Virgo Cluster include the beautiful Sombrero and Black-Eye galaxies, as well as the underrated pair M88 and M90. In a telescope at high magnification this pair broods alone in your eyepiece, with almost no foreground stars from our own galaxy to spoil the view.

• The center of the Virgo Cluster is 60 million light years away. The cluster is concentrated in a patch of sky in western Virgo, some 8-10 degrees wide.

• It’s no accident that big ellipticals gather near the center of the cluster. Their mutual gravitational attraction holds them close together.

• The spirals, on the other hand, which tend to be lighter and move faster, are strewn in a filamentary structure away from the core of the cluster. In time, the spirals find their way towards the center of the cluster. Some astronomers think large ellipticals were formed from spiral galaxies that merged as they were pulled into center of massive galaxy clusters.

• The modest Local Group of galaxies of which we’re a part is receding from the Virgo Cluster. But it may likely succumb to gravitational attraction and merge with this massive group in an indeterminate number of billions of years.

• The Virgo Cluster, the Local Cluster, and many others galaxy clusters form a much larger gravitationally-bound structure called the Local Supercluster. There are millions of galaxy superclusters spread across the universe.

Point a telescope towards the Virgo Cluster, and you’ll have no trouble seeing galaxies. The trick lies in sorting out which fuzzy spot is which. A good finder chart, dark sky, and lots of patience will help, as will a Go-To mount.

Try approaching the center of the cluster from M60 on the eastern edge, and move slowly towards the center. The massive ellipticals, each containing a trillion stars or more, are mostly featureless even in a large telescope. But the spirals may reveal structure as you increase from lower to higher magnification. The pretty spirals on the edge of the cluster, like NGC4565, M104, and M64, are much easier to find.

There is enough here for a hundred nights of patient viewing.

For a finder chart to help you navigate the Virgo Cluster, click here.

The prominent amateur astronomer Leland Copleand said he was intruigued by galaxies “not for what they seem to be, but for what they are. Each is a distant Milky Way, seen by light millions of years older than prehistoric man. They can help us gain true perspective– we and our world are the minutiae and curiosa– galaxies are the grand realities.”

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