The Corona Borealis Supercluster is a

supercluster 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 contains more than 54 galaxies), which in turn ...

located in the constellation

Corona Borealis Corona Borealis is a small constellation in the Northern Celestial Hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Its brightest stars form a se ...

and the most prominent example of its kind in the Northern Celestial Hemisphere. Dense and compact compared with other superclusters, its mass has been calculated to lie somewhere between 0.6 and 12 × 10¹⁶

solar mass The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

es (M⊙). It contains the galaxy clusters Abell 2056, Abell 2061,

Abell 2065 Abell 2065 is a highly concentrated galaxy cluster in the constellation of Corona Borealis containing over 400 member galaxies, the brightest of which are 16th magnitude. The cluster is more than one billion light-years from Earth. On a larger s ...

(the most massive galaxy cluster within the supercluster), Abell 2067, Abell 2079, Abell 2089, and Abell 2092. Of these, Abell 2056, 2061, 2065, 2067 and A2089 are gravitationally bound and in the process of collapsing to form a massive cluster. This entity has an estimated mass of around 1 × 10¹⁶ M⊙. If there is inter-cluster mass present, then Abell 2092 may also be involved. It has been estimated to be 100

megaparsecs The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, an ...

(330 million

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s) wide and 40 megaparsecs (130 million light years) deep. It has a redshift of 0.07, which is equivalent to a distance of around 265.5 megaparsecs (964 million light-years).

Observational history

Astronomers C. Donald Shane and

Carl A. Wirtanen Carl Alvar Wirtanen (November 11, 1910 – March 7, 1990) was an American astronomer and discoverer of comets and minor planets who worked at Lick Observatory. He was of Finnish ancestry. Wirtanen was born in Kenosha, Wisconsin. After visiti ...

were the first to note a concentration or "cloud" of "extragalactic nebulae" in the region during a large-scale survey of extragalactic structures in the sky. George Abell was the first to note the presence of what he called "second-order clusters", namely clusters of clusters in the first publication of his

Abell catalogue The Abell catalog of rich clusters of galaxies is an all-sky catalog of 4,073 rich galaxy clusters of nominal redshift ''z'' ≤ 0.2. This catalog supplements a revision of George O. Abell's original "Northern Survey" of 1958, wh ...

in 1958. Postman and colleagues were the first to study the supercluster in detail in 1988, calculating it to have a mass of 8.2 × 10¹⁵

solar masses The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of ...

, and contain the Abell clusters Abell 2061,

, Abell 2067, Abell 2079, Abell 2089, and Abell 2092. Abell 2124 lies 33 megaparsecs (110 million light-years) from the centre of the supercluster and has been considered part of the group by some authors. Abell 2069 lies close by but is more distant, with a line-of-sight association only.

References

{{reflist, refs= Galaxy superclusters Corona Borealis

Observational history

See also

References