# Virgo Cluster

The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the Virgo constellation. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group (containing the Milky Way galaxy) is a member. The Local Group actually experiences the mass of the Virgo Supercluster as the Virgocentric flow. It is estimated that the Virgo Cluster's mass is 1.2×10$^{15}$ M$_☉$ out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc.
Many of the brighter galaxies in this cluster, including the giant elliptical galaxy Messier 87, were discovered in the late 1770s and early 1780s and subsequently included in Charles Messier's catalogue of non-cometary fuzzy objects. Described by Messier as nebulae without stars, their true nature was not recognized until the 1920s.
The cluster extends across approximately 8 degrees centered in the constellation Virgo. Some of its most prominent members can be seen with binoculars and small telescopes, while a 6-inch telescope will reveal about 160 of the cluster's galaxies on a clear night. Its brightest member is the elliptical galaxy Messier 49.

## Characteristics

The cluster is a fairly heterogeneous mixture of spiral and elliptical galaxies. As of 2004, it is believed that the spiral galaxies of the cluster are distributed in an oblong prolate filament, approximately four times as long as it is wide, stretching along the line of sight from the Milky Way. The elliptical galaxies are more centrally concentrated than the spiral galaxies.
The cluster is an aggregate of at least three separate subclumps: Virgo A, centered on M87, a second centered on the galaxy M86, and Virgo B, centered on M49, with some authors including a Virgo C subcluster, centered on the galaxy M60 as well as a Low Velocity Cloud (LVC) subclump, centered on the large spiral galaxy NGC 4216. The giant elliptical galaxy M87 contains a supermassive black hole, whose event horizon was observed by the Event Horizon Telescope Collaboration in 2019.
Virgo A is the dominant subclump; its mass of approximately 10$^{14}$ M$_☉$ is approximately ten times larger than the other two subclumps. It contains a mixture of elliptical, lenticular, and spiral galaxies which are generally gas-poor,
The three subgroups are in the process of merging to form a larger single cluster, and are surrounded by other smaller galaxy clouds, mostly composed of spiral galaxies, known as N Cloud, S Cloud, and Virgo E that are in the process of infalling to merge with them, plus other farther isolated galaxies and galaxy groups (like the galaxy cloud Coma I) that are also attracted by the gravity of Virgo to merge with it in the future. This strongly suggests the Virgo cluster is a dynamically young cluster that is still forming.
Nearby aggregations known as M Cloud, W Cloud, and W' Cloud seem to be background systems independent of the main cluster.
The large mass of the cluster is indicated by the high peculiar velocities of many of its galaxies, sometimes as high as 1,600 km/s with respect to the cluster's center.
The Virgo cluster lies within the Virgo Supercluster, and its gravitational effect slows down the nearby galaxies. The large mass of the cluster has the effect of slowing down the recession of the Local Group from the cluster by approximately ten percent.
Molecular gasses in Virgo Cluster has been swept away by a huge cosmic broom that is preventing nearby galaxies from birthing new stars. The actual cause of it has been a long standing mystery in astrophysics. According to scientists, it occurs because of the extreme environment of the Virgo Cluster.

## Intracluster medium

As with many other rich galaxy clusters, Virgo's intracluster medium is filled with a hot, rarefied plasma at temperatures of 30 million kelvins that emits X-Rays. Within the intracluster medium (ICM) are found a large number of intergalactic stars (up to 10% of the stars in the cluster), including some planetary nebulae. It is theorized that these were expelled from their home galaxies by interactions with other galaxies. The ICM also contains some globular clusters, possibly stripped off dwarf galaxies, and even at least one star formation region.

## Galaxies

Below is a table of bright or notable objects in the cluster and their subcluster. In some cases a galaxy may be considered to be in a different subcluster by other researchers (sources:)
    Column 1: The name of the galaxy.
    Column 2: The right ascension for epoch 2000.
    Column 3: The declination for epoch 2000.
    Column 4: The blue apparent magnitude of the galaxy.
    Column 5: The galaxy type: E=Elliptical, S0=Lenticular, Sa,Sb,Sc,Sd=Spiral, SBa,SBb,SBc,SBd=Barred spiral, Sm,SBm,Irr=Irregular.
    Column 6: The angular diameter of the galaxy (arcminutes).
    Column 7: The diameter of the galaxy (thousands of light years).
    Column 8: The recessional velocity (km/s) of the galaxy relative to the cosmic microwave background.
    Column 9: Subcluster where the galaxy is located.
Cluster members :
| Designation | Coordinates (Epoch 2000) | Coordinates (Epoch 2000) | Apparent magnitude (blue) | Type | Angular size | Diameter (kly) | RV (km/s) | Subcluster |
| Designation | RA | Dec | Apparent magnitude (blue) | Type | Angular size | Diameter (kly) | RV (km/s) | Subcluster |
| Messier 98 | 12 13.8 | 14 54 | 10.9 | SBb | 9.8′ | 150 | 184 | Virgo A or N Cloud |
| NGC 4216 | 12 15.9 | 13 09 | 10.9 | SBb | 7.9′ | 120 | 459 | Virgo A, N Cloud, or LVC. |
| Messier 99 | 12 18.8 | 14 25 | 10.4 | Sc | 5.4′ | 80 | 2735 | Virgo A or N Cloud |
| NGC 4262 | 12 19.5 | 14 53 | 12.4 | S0 | 1.9′ | 30 | 1683 | Virgo A |
| NGC 4388 | 12 25.5 | 12 39 | 11.8 | SAb | 6.2′ | 85 | 2845 | Virgo A |
| Messier 61 | 12 21.9 | 04 28 | 10.2 | SBbc | 6.2′ | 100 | 1911 | S Cloud |
| Messier 100 | 12 22.9 | 15 49 | 10.1 | SBbc | 7.6′ | 115 | 1899 | Virgo A |
| Messier 84 | 12 25.1 | 12 53 | 10.1 | E$_1$ | 6.0′ | 90 | 1239 | Virgo A Markarian's Chain |
| Messier 85 | 12 25.4 | 18 11 | 10.0 | S0 | 7.1′ | 105 | 1056 | Virgo A |
| Messier 86 | 12 26.2 | 12 57 | 9.9 | E$_3$ | 10.2′ | 155 | 37 | Virgo A or own subgroup. Markarian's Chain |
| NGC 4435 | 12 27.7 | 13 05 | 11.7 | S0 | 3.0′ | 45 | 1111 | Virgo A |
| NGC 4438 | 12 27.8 | 13 01 | 11.0 | Sa | 8.7′ | 130 | 404 | Virgo A |
| NGC 4450 | 12 28.5 | 17 05 | 10.9 | Sab | 5.1′ | 80 | 2273 | Virgo A |
| Messier 49 | 12 29.8 | 08 00 | 9.3 | E$_2$ | 9.8′ | 150 | 1204 | Virgo B |
| Messier 87 | 12 30.8 | 12 23 | 9.6 | E$_{0–1}$ | 9.8′ | 980 | 1204 | Virgo A |
| Messier 88 | 12 32.0 | 14 25 | 10.3 | Sb | 6.8′ | 100 | 2599 | Virgo A |
| NGC 4526 | 12 32.0 | 07 42 | 10.6 | S0 | 7.1′ | 105 | 931 | Virgo B |
| NGC 4527 | 12 34.1 | 02 39 | 12.4 | Sb | 4.6′ | 69 | 1730 | S Cloud |
| NGC 4536 | 12 34.4 | 02 11 | 11.1 | SBbc | 7.2′ | 115 | 2140 | S Cloud |
| Messier 91 | 12 35.4 | 14 30 | 11.0 | SBb | 5.2′ | 80 | 803 | Virgo A |
| NGC 4546 | 12 35.5 | −03 48 | 11.3 | S0 | 2.3' | 30 | 1054 | S Cloud |
| NGC 4550 | 12 35.5 | 12 13 | 12.5 | S0 | 3.2′ | 50 | 704 | Virgo A |
| Messier 89 | 12 35.7 | 12 33 | 10.7 | E$_0$ | 5.0′ | 75 | 628 | Virgo A |
| NGC 4567 | 12 36.5 | 11 15 | 12.1 | Sbc | 2.8′ | 40 | 2588 | Virgo A |
| NGC 4568 | 12 36.6 | 11 14 | 11.7 | Sbc | 4.4′ | 65 | 2578 | Virgo A |
| Messier 90 | 12 36.8 | 13 10 | 10.2 | SBab | 10.5′ | 160 | 87 | Virgo A |
| NGC 4571 | 12 36.9 | 14 13 | 11.9 | Sc | 3.7′ | 55 | 659 | Virgo A |
| Messier 58 | 12 37.7 | 11 49 | 10.6 | SBb | 5.6′ | 85 | 1839 | Virgo A |
| Messier 59 | 12 42.9 | 11 39 | 10.8 | E$_5$ | 5.0′ | 75 | 751 | Virgo A or Virgo E |
| Messier 60 | 12 43.7 | 11 33 | 9.8 | E$_2$ | 7.2′ | 110 | 1452 | Virgo A, Virgo E, or Virgo C |
| NGC 4651 | 12 43.7 | 16 24 | 11.4 | Sc | 4.0′ | 60 | 1113 | |
| NGC 4654 | 12 43.9 | 13 08 | 11.1 | SBc | 5.0′ | 75 | 1349 | Virgo A |
Fainter galaxies within the cluster are usually known by their numbers in the Virgo Cluster Catalog, particularly members of the numerous dwarf galaxy population.