Abell 370 is a

galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-l ...

located nearly 5 billion

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 away from the Earth (at

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

''z'' = 0.375), in the constellation

Cetus Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus (mythology), Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water- ...

. Its core is made up of several hundred galaxies. It was catalogued by George Abell, and is the most distant of the clusters he catalogued. In the 1980s astronomers of

Toulouse Observatory The Toulouse Observatory (french: Observatoire de Toulouse) is located in Toulouse, France and was established in 1733. It was founded by ''l'Académie des Sciences, Inscriptions et Belles-Lettres de Toulouse'' ("Academy of Science, Inscriptions ...

discovered a

gravitational lens A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...

in space between Earth and Abell 370. A curious arc had been observed earlier near the cluster, but the astronomers were able to recognize it as this phenomenon.

Gravitational lensing

Abell 370 appears to include several arcs of light, including the largest ever discovered with 30" long. These arcs or deformations are

mirage A mirage is a naturally-occurring optical phenomenon in which light rays bend via refraction to produce a displaced image of distant objects or the sky. The word comes to English via the French ''(se) mirer'', from the Latin ''mirari'', meanin ...

s caused by

gravitational lensing A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...

of massive and dark objects located between the observer and the distant galaxies. This cluster shows an apparent magnitude of +22. In 2002, astronomers used this lensing effect to discover a galaxy,

HCM-6A HCM-6A is an LAE galaxy that was found in 2002 by Esther Hu and Lennox Cowie from the University of Hawaii and Richard McMahon from the University of Cambridge, using the Keck II Telescope in Hawaii. HCM-6A is located behind the Abell 37 ...

, 12.8 billion light years away from Earth. At the time it was the furthest known galaxy. In 2009, study in the field of Abell 370 revealed a grouping of background galaxies lensed and distorted by the cluster into an arc with the appearance of a dragon, hence nicknamed The Dragon by NASA scientists. Its head is composed of a spiral galaxy, with another image of the spiral composing the tail. Several other images form the body of the dragon, all overlapping. These galaxies all lie approximately 5 billion light years away.

Gallery

File:BUFFALO’s view on Abell 370.jpg, BUFFALO’s survey view on Abell 370. File:Abell 370 Parallel Field with Asteroids.jpg, Abell 370 Parallel Field with Asteroids. File:The last of the Frontier Fields — Abell 370.jpg, Abell 370 is one of the first galaxy clusters in which astronomers observed the phenomenon of gravitational lensing.

References

Gravitationally lensed images in Abell 370
Authors: Grossman, S. A. & Narayan, R. * Image of Abell 370 released bu STScI HST in May 2017 : http://hubblesite.org/news_release/news/2017-20

External links

*

{{DEFAULTSORT:Abell 370 Galaxy clusters

370 __NOTOC__ Year 370 ( CCCLXX) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Valens (or, less frequently, year 1123 '' ...

Abell richness class 0 Cetus (constellation)

Gravitational lensing

Gallery

See also

References

External links