The Virgo Galaxy Cluster – A Complete Guide for the Backyard Astronomer

The night sky is full of objects to see and wonder at, and we astronomers know that. No matter how long you've been stargazing, there's always something new to point your telescope at.

Take, for instance, the Virgo Cluster. It's one of the richest places in the night sky, in terms of the number of objects it contains (over 1200 galaxies according to the table on this page).

Virgo cluster of galaxies

The Virgo Cluster of Galaxies (source)

However, any​ meaningful observation of the cluster requires a good knowledge of it.

This guide helps you with that. In it, you'll learn everything you need to know to plan your own session of viewing many of the galaxies in this group... and discover some little-known elements of it to share with your astronomy club.

So let's begin!

Virgo Cluster Basics

The Virgo Cluster is a conspicuous object in the night sky. It's also the farthest object from our galaxy which has a physical connection with us.

It is a gigantic cluster of galaxies found in the constellation of Virgo. Another such cluster is the Local Group, which our own Milky Way and the Andromeda Galaxy are part of.

Our Local Group and the Virgo Cluster are a part of an even bigger object - The Virgo Supercluster.

virgo supercluster

Virgo Supercluster, with our Local Group centered (source)

This enormous object is bound together by the collective gravity of the constituent galaxies and spans an unimaginable 110million light years of space.

To help get your head around such a phenomenal structure, below is a 3D map showing the various subclusters in the Virgo Supercluster:

3D map of Virgo Supercluster

3D version of the Virgo Supercluster (source)

If your mind is not blown yet, it will be when you learn that the Virgo Supercluster is just one of 10 million superclusters in the observable universe!

Let's drill back down to the more manageable Virgo Cluster.

Although it is vast, it is also a very long way from here - around 53million light years, in fact. So, in our sky, the entire cluster fits in an area about 8 to 10 degrees wide.

It consists of spiral, dwarf and giant elliptical galaxies arranged in three 'subclumps' or smaller clusters:

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M87 / Messier A

Virgo A has M87 at its center (source).

M86

An unnamed cluster surrounds M86 (source).

M49 in Virgo

Virgo B has the brightest galaxy, M49 (source).

All three subclumps are slowly falling into each other under gravity and will eventually form one single cluster.

M49, M86 and M87 were first cataloged by Charles Messier (although he thought they were nebulae) along with 13 other galaxies. He made note of them in the 1770s and 1780s, so it's a safe bet that your telescope is better than his.

With that in mind, good seeing, a dark site, and a scope of around 6", it's not unreasonable to target seeing 20 or more of the galaxies in the Virgo Cluster.

You can buy our ready-made observing list of the brightest 30 galaxies for just $1.99 - compatible with Sky Safari 5.

With our target set, let's get into how we're going to achieve it. We'll begin with finding the Virgo Cluster in the night sky.

Ideal Equipment for Seeing the Virgo Cluster

The brightest element in the galaxy cluster is M49, with an apparent magnitude of 9.3. This is well beyond even the best eyesight and so you will need to make use of a telescope to enjoy any of the galaxies in the cluster.

As this thread from Cloudy Nights reports, a 6" aperture and dark skies is enough to see the best of the Virgo Cluster. With an 8" scope at your disposal, the 30-or-so galaxies brighter than magnitude 12.0 are within reach. ​

You can find the SkyWatcher light-bucket​ 8" Dob for under $500 on this page.

Or, if you prefer go-to capability - which certainly helps this seeing challenge - then the Celestron Nexstar 8SE is for you. Read our full review here.

You will get best results using an eyepiece with a wide field of view. Something like this Orion 20mm Plössl on Amazon has 52° apparent FOV and is a great price.

If you have more cash (this next one is 4x the price on Amazon of the Plössl) then Orion's 17mm Stratus eyepiece yields a 68° FOV and fits both 1.25" and 2" scopes.

Finally, for finding your way around, you can't go wrong with a red flashlight and Sky & Telescope's Pocket Sky Atlas. This has a dedicated page for the cluster with good - but not overwhelming - levels of detail.

How to Find the Virgo Cluster of Galaxies

Finding galaxies in Virgo needs a simple application of the star-hopping technique, or a goto telescope programmed with the coordinates (which you can get for Sky Safari 5 here).

Additionally, it will be useful to have Stellarium or Sky Safari 5, which the following screenshots come from. You can also use the essential Pocket Sky Atlas, which has a page dedicated to the Virgo Galaxy Cluster.

Let's begin. First, you'll need to spot the Virgo constellation. Leo will be right beside it.

Locate these three stars: Auva and Vindemiatrix in Virgo and Denebola in Leo (circled in red, below). These are the loose boundary for the Virgo Cluster of galaxies and make the perfect starting reference point.

Where to find the Virgo Galaxy Cluster

Where to find the Virgo Galaxy Cluster - Screenshot from Sky Safari 5 Plus (click to enlarge)

Markarian's Chain

Before we (finally) get into looking for individual galaxies, there is one other observing challenge you should know about.

Markarian's Chain is a line of 8 galaxies - all gravitationally associated with each other - that string out in an arc. See the image below and note it includes M84 and M86.

Markarian's Chain in Virgo Cluster

Markarian's Chain. Right image shows NGC numbers. Sky Safari 5 screenshots. (Click to zoom)

A wider field of view will show you many of them at once; using higher magnifying power when you have them in sight will enhance details.

Markarian's chain also contains the Eyes Galaxies. These are NGC 4435 and 4438. Together, they are bright, round galaxies named after two Greek words for 'eye': Oppa Virginis and Omma Virginis.

The Eyes Galaxies in Markarian's Chain

The Eyes Galaxies, NGC 4438 (top) and NGC4435 (source)

This small chain of eight galaxies is a nice challenge for an evening's viewing and rewards with a glow of satisfaction when you 'bag' all of them.

The eight galaxies of Markarian’s chain are included as a stand-alone observation list with our Sky Safari 5 Virgo Cluster list.

Seeing Individual Galaxies in The Cluster

Before you start looking for the galaxies themselves, remember two important things about seeing them:

  1. More light is better, so bigger telescope apertures give better results than smaller ones. An 8" aperture will yield superior sights to a 6".
  2. Galaxies are easier to find in a wider field of view. Start with lower magnification and only increase it once you've located the object you are looking for

With that said, let's dive into the galaxies themselves...

As mentioned earlier, there are 16 Messier objects - all galaxies - in the Virgo Cluster.

Whilst they are plentiful, and some are quite bright, don't underestimate the challenge of spotting individual objects.

The challenge in seeing them comes from the fact they are mostly faint and they are close to each other. Through the eyepiece, they are not much more than grey, fuzzy patches (although a decent telescope filter can improve detail).

There are three routes to seeing the best this cluster has to offer:

  1. Figure it out for yourself using a star atlas and Stellarium
  2. The the guide in Kenneth Glyn Jones' book Messiers, Nebulae and Star Clusters. It is part reproduced below and can be freely downloaded from SEDs
  3. Grab our pre-programed observation list for $1.99. It covers the brightest 30 galaxies in the Virgo Cluster and is compatible with Sky Safari 5.

Extract from SEDs Guide to Observing the Virgo Cluster

Click the picture below to get a larger version.

Summary

The Virgo Cluster of Galaxies is an area of our sky rich in relatively bright galaxies.

In this article we've shared with you how easy it is to find the area, how vast it is and the unimaginable distances involved.

We've also shared the most important factor for any backyard astronomer: how to see it!

If you want our Sky Safari 5 observation list for yourself (for only $1.99) click here. If you don't own Sky Safari 5 yet and would like to find out more, click the relevant link below:

Resources


Nine Painful Truths of Backyard Astronomy

The 9 Painful Truths of Backyard Astronomy...

There are some harsh realities when you take up astronomy, this brief guide will share with you:

  • The TRUTHS you need to be aware of
  • How we get past them to receive the JOY of the night sky

Links: Please note, some of the links in this article are affiliate links. You can find out more by clicking on 'affiliate links' in the footer.