Virgo Supercluster

Space is filled with huge groups of galaxies.

One of these is called the Virgo Supercluster. It is very large. It holds many galaxy groups and clusters. Our own home is in a small group. This small group sits near the edge. It spins around the center of the supercluster. Most of the galaxies live in a flat disk. This disk looks like a long, thin shape. The supercluster is part of an even bigger web. This big web is called Laniakea. It is a very amazing place to study.

The Virgo Supercluster is a massive group of galaxies. It is one of about 10 million superclusters in the universe. This supercluster is centered on the Virgo Cluster. Our own home is in the Local Group. This group holds the Milky Way and Andromeda galaxies. The Local Group sits near the edge of the supercluster. It moves around the center.

Most galaxies in the supercluster live in a flat disk. This disk is called the Virgo Strand. It is a long, thin shape. The disk is part of a larger galaxy filament. A filament is a long chain of galaxies. This chain connects many different clusters.

Scientists found that the supercluster is part of something even bigger. This huge structure is called Laniakea. Laniakea is a supercluster cocoon. This is a term for a very large area. It acts like a basin of attraction. This means it pulls things toward it. The supercluster is moving toward the Great Attractor. This is a center of mass within Laniakea. This helps us understand how the universe moves.

The Virgo Supercluster is a huge collection of galaxies. It is one of about 10 million superclusters in the observable universe. This structure is roughly centered on the Virgo Cluster. Our own home, the Local Group, sits near one edge. The Local Group includes the Milky Way and Andromeda galaxies. It revolves around the center of the supercluster.

This supercluster has a very interesting shape. Most of its galaxies live in a flat disk called the Virgo Strand. This disk is a thin shape that is much longer than it is wide. It is part of a larger galaxy filament. A filament is a long chain of galaxies that connects different areas. The Virgo Strand connects the Hydra-Centaurus and the Perseus–Pisces Superclusters.

People have been studying these distant objects for a long time. In 1863, William and John Herschel published notes about many nebulae. They noticed many were in the constellation Virgo. In 1953, an astronomer named Gérard de Vaucouleurs called this a Local Supergalaxy. He changed the name to Local Supercluster in 1958. Later, Harlow Shapley suggested the term Metagalaxy in 1959. Scientists debated if it was a real structure until the late 1970s.

There are many specific facts about this place. The supercluster contains at least 100 galaxy groups and clusters. Its volume is 7,000 times larger than the Local Group. It is also 100 billion times larger than the Milky Way. Most galaxies live in 11 specific clouds. These include the Virgo Cluster and the Canes Venatici cloud. The Virgo Cluster holds one-third of the galaxies in the disk.

Space can be thought of like a collection of soap bubbles. Most of the volume in the supergalactic plane is actually empty space. Galaxies live at the intersections where these cosmic bubbles meet. We also know that much of the supercluster is made of dark matter. We know this because the mass-to-light ratio is very high. This ratio is about 300 times that of our sun. This mass helps pull everything toward the Great Attractor.

The Virgo Supercluster, also known as the Local Supercluster, is a massive collection of galaxies. It serves as a large-scale structure in our corner of the universe. This supercluster contains the Virgo Cluster at its heart and the Local Group near its edge. The Local Group is our own cosmic neighborhood, containing the Milky Way and the Andromeda galaxy. Within this supercluster, there are at least 100 different galaxy groups and clusters. It is just one of approximately 10 million superclusters found in the observable universe.

The structure of the Virgo Supercluster is divided into two distinct parts. In 1982, researcher R. Brent Tully described these components. The first part is an appreciably flattened disk. This disk contains about two-thirds of the supercluster's luminous galaxies. It is a thin ellipsoid with a long-to-short axis ratio between 6:1 and 9:1. The second part is a roughly spherical halo. This halo contains the remaining one-third of the galaxies. The Local Group sits on the outskirts of the supercluster within a small filament.

The main body of the disk is called the Virgo Strand. This strand is part of a much larger galaxy filament known as the Centaurus–Virgo–PP Filament. This filament connects the Hydra-Centaurus and the Perseus–Pisces Superclusters. The Virgo Strand itself has two main branches. The upper branch includes the Virgo Southern Extension, the Virgo Cluster, and the Ursa Major Cluster. The lower branch consists of the Crater and Leo Clouds. Most of the supercluster's volume is actually empty space, which astronomers call a void. You can imagine this like soap bubbles, where galaxies live at the intersections of the bubbles.

Humans have been mapping these structures for many years. In 1863, William and John Herschel published a large sample of nebulae. They noticed an excess of these objects in the constellation Virgo. In 1953, astronomer Gérard de Vaucouleurs argued this was a large-scale structure. He first called it the Local Supergalaxy before changing the name to Local Supercluster in 1958. Harlow Shapley also suggested the term Metagalaxy in 1959. Scientists debated if this was a real structure throughout the 1960s and 1970s. Redshift surveys in the late 1970s and early 1980s finally proved the galaxies were concentrated along a supergalactic plane.

The distribution of galaxies within the supercluster is not random. The number of galaxies decreases as you move away from the Virgo Cluster. Most luminous galaxies are concentrated in just 11 specific clouds. These include the Canes Venatici, Virgo Cluster, and Leo II clouds. The Virgo Cluster alone holds one-third of the galaxies found in the disk. To understand the scale, the Virgo Supercluster's volume is 7,000 times that of the Local Group. It is also 100 billion times larger than the Milky Way.

Recent studies have changed how we define these massive structures. A 2014 study suggested the Virgo Supercluster is part of an even larger structure. This larger structure is centered on the Great Attractor and is called the Laniakea Supercluster. Laniakea acts as a basin of attraction, which is a region where matter flows toward a center. Because of this, some scientists suggest calling Laniakea a supercluster cocoon. This helps distinguish the massive basin from the smaller, high-density regions like the Virgo Supercluster. All matter within 50 Mpc is experiencing a bulk flow toward the Norma Cluster.

There is also a great deal of invisible matter in the supercluster. The Virgo Supercluster has a very high mass-to-light ratio. This ratio is about 300 times that of our sun. In comparison, the Milky Way has a ratio of only 63.8. This high ratio provides strong evidence for the existence of dark matter. Dark matter is a substance that provides extra gravity but does not emit light. This extra mass helps drive the movement of galaxies toward the Great Attractor. The entire Laniakea structure is currently moving toward the Shapley Supercluster.