A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group, which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster, which is part of the Pisces–Cetus Supercluster Complex. The large size and low density of superclusters means that they, unlike clusters, expand with the Hubble expansion. The number of superclusters in the observable universe is estimated to be 10 million.
The Local Supercluster, 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 and clusters are located within its diameter of 33 megaparsecs. The Virgo Supercluster is one of about 10 million superclusters in the observable universe and is in the Pisces–Cetus Supercluster Complex, a galaxy filament.
Jaan Einasto is an Estonian astrophysicist and one of the discoverers of the large-scale structure of the Universe.
The Hydra–Centaurus Supercluster, or the Hydra and Centaurus Superclusters, was a previously defined supercluster in two parts, which prior to the identification of Laniakea Supercluster in 2014 is the closest neighbour of the former Virgo Supercluster. Its center is located about 39 Mpc (127 Mly) away, with it extending to a maximum distance of around 69 Mpc (225 Mly).
Messier 94 is a spiral galaxy in the mid-northern constellation Canes Venatici. It was discovered by Pierre Méchain in 1781, and catalogued by Charles Messier two days later. Although some references describe M94 as a barred spiral galaxy, the "bar" structure appears to be more oval-shaped. The galaxy has two ring structures.
The Las Campanas Redshift Survey is considered the first attempt to map a large area of the universe out to a redshift of z = 0.2. It was begun in 1991 using the Las Campanas telescope in Chile to catalog 26418 separate galaxies. It is considered one of the first surveys to document the so-called "end of greatness" where the Cosmological Principle of isotropy could be seen. Superclusters and voids are prominent features in the survey.
Density contrast is a parameter used in galaxy formation to indicate where there are local enhancements in matter density.
The Sloan Great Wall (SGW) is a cosmic structure formed by a giant wall of galaxies. Its discovery was announced from Princeton University on October 20, 2003, by J. Richard Gott III, Mario Jurić, and their colleagues, based on data from the Sloan Digital Sky Survey.
The Pavo–Indus Supercluster is a neighboring supercluster located about 60–70 Mpc (196–228 Mly) away in the constellations of Pavo, Indus, and Telescopium. The supercluster contains three main clusters, Abell 3656, Abell 3698, and Abell 3742.
NGC 4889 is an E4 supergiant elliptical galaxy. It was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a median distance of 94 million parsecs from Earth. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The gamma ray bursts from the galaxy extend out to several million light years of the cluster.
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 being the Hercules-Corona Borealis Great Wall at around 3 gigaparsecs (9.8 Gly) in length—and form the boundaries between voids. Due to the accelerating expansion of the universe, the individual clusters of gravitationally bound galaxies that make up galaxy filaments are moving away from each other at an accelerated rate; in the far future they will dissolve.
The Hercules Superclusters refers to a set of two nearby superclusters of galaxies.
The Sculptor Wall is a superstructure of galaxies relatively near to the Milky Way Galaxy, also known as the Sculptor superclusters.
The Laniakea Supercluster or the Local Supercluster is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies.
The Hyperion proto-supercluster is the largest and earliest known proto-supercluster, 5,000 times the mass of the Milky Way and seen at 20% of the current age of the universe. It was discovered in 2018 by analysing the redshifts of 10,000 objects observed with the Very Large Telescope in Chile.
NGC 3294 is a spiral galaxy in the constellation Leo Minor. It was discovered by William Herschel on Mar 17, 1787. It is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster. The galaxy is located at a distance of 98 million light years and is receding with a heliocentric radial velocity of 1,586 km/s. The morphological class of NGC 3294 is SA(rs)bc, which means this is a spiral galaxy with no central bar (SA), an incomplete inner ring structure (rs), and moderately wound spiral arms (bc).
Alcyoneus is a low-excitation, Fanaroff–Riley class II radio galaxy located 3.5 billion light-years from Earth, with host galaxy SDSS J081421.68+522410.0. It is located in the constellation Lynx and it was discovered in Low-Frequency Array (LOFAR) data by a team of astronomers led by Martijn Oei. As of 2024, it has the second-largest extent of radio structure of any radio galaxy identified, with lobed structures spanning 5 megaparsecs across, described by its discoverers at the time as the "largest known structure of galactic origin." It has since been superseded by another radio galaxy, Porphyrion, with lobed structures of 7 megaparsecs.
NGC 4324 is a lenticular galaxy located about 85 million light-years away in the constellation Virgo. It was discovered by astronomer Heinrich d'Arrest on March 4, 1862. NGC 4324 has a stellar mass of 5.62 × 1010M☉, and a baryonic mass of 5.88 × 1010M☉. The galaxy's total mass is around 5.25 × 1011M☉. NGC 4324 is notable for having a ring of star formation surrounding its nucleus. It was considered a member of the Virgo II Groups until 1999, when its distance was recalculated and it was placed in the Virgo W Group.
