The Leo II Groups, Leo II Cloud, or simply the Leo Cloud is a

galaxy filament In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50 to 80 megaparsecs ()—with the largest found to date b ...

consisting of at least 18

galaxy group A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxi ...

s. It is located approximately 86 Mly (26 Mpc) from the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

. The Leo Cloud in supergalactic SGY coordinates is physically behind the

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 ...

. Eventually, over the next

Hubble time Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther a galaxy is from the Earth, the faster ...

, the galaxy groups that make up the Leo II Cloud will infall and merge with the Virgo Cluster. The Leo Cloud, along with the

Crater Cloud A crater is a landform consisting of a hole or depression on a planetary surface, usually caused either by an object hitting the surface, or by geological activity on the planet. A crater has classically been described as: "a bowl-shaped pi ...

which contains the NGC 4038 Group, is actually the same branch of a larger

that extends from the

Centaurus Cluster The Centaurus Cluster (A3526) is a cluster of hundreds of galaxies, located approximately 170 million light-years away in the Centaurus constellation. The brightest member galaxy is the elliptical galaxy NGC 4696 (~11m). The Centaurus clust ...

through the

and continues through the

Ursa Major Cluster The Ursa Major Cluster (Ursa Major I Cluster, UMa I ClG) is a spiral-rich galaxy cluster of the Virgo Supercluster. Some of its largest members are NGC 3631, NGC 3953, M109 on North (M109 Group) and NGC 3726, NGC 3938, NGC 4051 on South. ...

, known as the

Virgo Strand The Local Supercluster (LSC or LS), or Virgo Supercluster is a formerly defined supercluster containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least 100 galaxy groups a ...

. The Virgo Strand is the main component of the

Virgo Supercluster The Local Supercluster (LSC or LS), or Virgo Supercluster is a formerly defined supercluster containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least 100 galaxy group ...

and is made of two branches with the lower branch consisting of the Leo and Crater clouds, while the upper branch is known as the

Virgo Southern Extension The Virgo II Groups, also known as the Virgo II Cloud, Virgo Southern Extension, or the Virgo S Cloud, are a series of at least 100 galactic clusters and individual galaxies stretching approximately off the southern edge of the Virgo Supercluste ...

Virgo II Groups The Virgo II Groups, also known as the Virgo II Cloud, Virgo Southern Extension, or the Virgo S Cloud, are a series of at least 100 galactic clusters and individual galaxies stretching approximately off the southern edge of the Virgo Supercluste ...

. The Leo Cloud itself is actually composed of two filaments, the Leo II A and Leo II B filaments. The Leo II A filament consists of the majority of the cloud, while the Leo II B filament consists of a sparse region of the cloud. The Leo Cloud, like the Virgo III Cloud, is prolate and points toward the

List of groups

Below is a list of groups in the Leo Cloud according to astronomer

Brent Tully Richard Brent Tully (born March 9, 1943) is a Canadian-born American astronomer at the Institute for Astronomy in Honolulu, Hawaii. Born in Toronto, Ontario, and raised in Vancouver, British Columbia, Tully's specialty is the astrophysics of ga ...

. : Column 1: The name of the group in Tully's NBGG : Column 2: The right ascension for epoch 2000. : Column 3: The declination for epoch 2000. : Column 4: Number of members of the group. : Column 5: Brightest member of the group : Column 6: Redshift of the group. : Column 7: Distance of the group (Millions of light-years). : Column 8: Cross-Identifications with other catalogs. (Sources for data columns:)

References

{{Reflist Galaxy filaments Virgo Supercluster

List of groups

See also

References