Virgo Cluster

A large group of star cities lives together.

This group is called the Virgo Cluster. It has about 1,300 star cities in it. Some say there are even more.

These star cities come in different shapes. Some look like swirls. Others look like round balls.

This big group is part of a much larger home.

Our own home is in this large group too.

You can see some of these cities with small tools. A small tool helps you see many of them.

It is a very busy place in space.

The Virgo Cluster is a huge group of galaxies.

It is about 53.8 million light-years away. A light-year is how far light travels in one year. This cluster has about 1,300 galaxies. Some scientists think there may be 2,000 galaxies there.

The cluster is part of a much larger group. This larger group is the Virgo Supercluster.

Our own home, the Milky Way, lives in this supercluster too. The big mass of the cluster pulls on things. It even slows down how fast our home moves away.

Galaxies in the cluster have different shapes. Some are spiral galaxies that look like swirls. Others are elliptical galaxies that look like round balls. Many elliptical galaxies stay near the center.

The space between galaxies is not empty. It is filled with a hot gas called plasma.

This plasma is very hot. It can even blow gas out of galaxies. This happens through a way called ram pressure stripping. This can stop a galaxy from making new stars.

The Virgo Cluster is a massive group of galaxies. It sits in the Virgo constellation. This cluster is about 53.8 million light-years away. It acts as the heart of the larger Virgo Supercluster. Our own home, the Milky Way, is part of this supercluster too.

The cluster's huge mass even pulls on our Local Group. This pull is called the Virgocentric flow. It slows down how fast we move away from the cluster. This shows how much gravity can affect the whole universe.

Inside the cluster, galaxies work in many different ways. Some are spiral galaxies that look like long filaments. These spirals are spread out in an oblong shape. Other galaxies are elliptical, which means they look more like round balls. These elliptical galaxies tend to stay near the center.

The cluster is also made of smaller clumps. There is a large group called Virgo A. This group is ten times larger than the others. Other groups include Virgo B and Virgo C. Scientists think these groups are still merging together.

People have been looking at these galaxies for a long time. In the late 1770s, people found many bright members. Charles Messier added them to his famous catalogue. He called them nebulae because they looked fuzzy. He thought they were clouds without stars.

It took until the 1920s to know their true nature. Now we know they are actually entire galaxies. In 2019, the Event Horizon Telescope Collaboration saw something special. They observed the event horizon of a black hole in M87. This is a giant black hole at the center of a galaxy.

There are many important numbers to know about this place. The cluster has about 1,300 to 2,000 member galaxies. Its mass is huge within a radius of 2.2 megaparsecs.

Some galaxies move very fast due to gravity. Their speeds can reach 1,600 kilometers per second. The space between galaxies is filled with hot plasma. This plasma is 30 million kelvins in temperature. It even emits X-rays that we can detect. This hot gas can strip gas away from galaxies. This process is called ram pressure stripping.

Looking at the Virgo Cluster helps us understand our place in space. You can see some of its brightest members with binoculars. A 6-inch telescope can show you 160 galaxies on a clear night. One of the brightest members is Messier 49.

Another famous one is the giant galaxy Messier 87. These distant objects show us how galaxies grow and change. They are part of a living, moving cosmic neighborhood. Studying them helps us learn how the whole universe works.

The Virgo Cluster is a massive collection of galaxies located in the Virgo constellation. It serves as the central heart of the much larger Virgo Supercluster. Our own Milky Way galaxy is a member of the Local Group, which is part of this supercluster. Because of its immense gravity, the Local Group experiences a movement known as the Virgocentric flow. This flow is caused by the massive pull of the Virgo Cluster. The cluster is located approximately 53.8 million light-years away from Earth.

This cluster is not a single, solid object, but a dynamic collection of many parts. It is composed of roughly 1,300 to 2,000 member galaxies. Scientists believe the cluster is still forming because its various subgroups are currently merging. The cluster is organized into several distinct subclumps. The largest is Virgo A, which is centered on the galaxy Messier 87. Virgo A is dominant, with a mass about ten times larger than the other groups. Other identified subclumps include Virgo B, centered on Messier 49, and Virgo C, centered on Messier 60. There is also a Low Velocity Cloud subclump centered on the spiral galaxy NGC 4216.

The galaxies within the cluster are a diverse, heterogeneous mixture. They are generally categorized into spiral and elliptical types. The elliptical galaxies, which are shaped like rounded spheres, are more centrally concentrated. In contrast, the spiral galaxies are distributed in an oblong, prolate filament. This filament is about four times as long as it is wide. It stretches along our line of sight from the Milky Way. Some galaxies in the cluster are also described as lenticular, which is a shape between spiral and elliptical.

Human understanding of the Virgo Cluster has changed significantly over time. In the late 1770s and early 1780s, astronomers discovered many of the brightest members. Charles Messier included these objects in his famous catalogue of non-cometary fuzzy objects. At that time, he described them as nebulae without stars. It was not until the 1920s that the true nature of these objects was recognized. We now know they are entire galaxies rather than simple clouds of gas. In 2019, the Event Horizon Telescope Collaboration provided a major breakthrough by observing the event horizon of a supermassive black hole located in M87.

The cluster contains a vast amount of matter and energy. The mass of the cluster is measured out to a radius of about 2.2 megaparsecs. This massive presence causes many galaxies to move at very high peculiar velocities. Some galaxies travel at speeds as high as 1,600 kilometers per second relative to the cluster center. The space between these galaxies is not empty; it is filled with the intracluster medium. This medium is a hot, rarefied plasma reaching temperatures of 30 million kelvins. This plasma is so energetic that it emits X-rays.

Interactions within the intracluster medium lead to fascinating and intense processes. One such process is called ram pressure stripping. This occurs when the pressure from the dense intracluster medium removes molecular gas from a galaxy. This loss of gas can lead to the quenching of star formation, meaning the galaxy stops making new stars. The medium also contains intergalactic stars, which may make up 10% of the cluster's total stars. These stars may have been expelled from their home galaxies during cosmic interactions. The medium also contains globular clusters and even at least one star formation region.

Studying the Virgo Cluster provides a window into the larger structure of the universe. The cluster's gravity is strong enough to affect the movement of nearby galaxy groups. It slows down the recession of the Local Group from the cluster by about ten percent. The cluster is surrounded by smaller galaxy clouds, such as the N Cloud, S Cloud, and Virgo E. These clouds are currently infalling to merge with the main cluster. By observing these movements, astronomers can see how large-scale structures in the cosmos grow and evolve over billions of years.