The NGC 5679 group, also known as Arp 274, is a triplet of

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

MCG The Melbourne Cricket Ground (MCG), also known locally as "The 'G", is an Australian sports stadium located in Yarra Park, Melbourne, Victoria. Founded and managed by the Melbourne Cricket Club, it is the largest stadium in the Southern Hem ...

+1-37-36, MCG+1-37-35 and MCG+1-37-34, spanning about

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 and at some 400 million light-years from Earth in the constellation

Virgo Virgo may refer to: *Virgo (astrology), the sixth astrological sign of the zodiac *Virgo (constellation), a constellation *Virgo Cluster, a cluster of galaxies in the constellation Virgo *Virgo Stellar Stream, remains of a dwarf galaxy *Virgo Supe ...

. Arp 274 refers to the

Atlas of Peculiar Galaxies The ''Atlas of Peculiar Galaxies'' is a catalog of peculiar galaxies produced by Halton Arp in 1966. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology. The p ...

, compiled by

Halton Arp Halton Christian "Chip" Arp (March 21, 1927 – December 28, 2013) was an American astronomer. He was known for his 1966 ''Atlas of Peculiar Galaxies'', which (it was later theorized) catalogues many examples of interacting and merging galaxie ...

in 1966. Galaxies 269 through 274 in his catalogue are galaxies that appear to have connected

arms Arms or ARMS may refer to: *Arm or arms, the upper limbs of the body Arm, Arms, or ARMS may also refer to: People * Ida A. T. Arms (1856–1931), American missionary-educator, temperance leader Coat of arms or weapons *Armaments or weapons **Fi ...

. NGC 5679 was imaged by

Hubble The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

in 2009, in a combination of blue,

visible Visibility, in meteorology, is a measure of the distance at which an object or light can be seen. Visibility may also refer to: * A measure of turbidity in water quality control * Interferometric visibility, which quantifies interference contrast ...

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

and Hα filters. The photograph shows that all three galaxies, especially the galaxies on the left and right, are

starburst galaxies A starburst galaxy is one undergoing an exceptionally high rate of star formation, as compared to the long-term average rate of star formation in the galaxy or the star formation rate observed in most other galaxies. For example, the star formatio ...

, meaning that there is currently a large amount of

star formation Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space

in the galaxies.

Interstellar dust Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...

can be seen between the areas of star formation. Two bright stars can be seen just above the galaxy on the right side; these are foreground stars that are actually part of our own galaxy.

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 ...

measurements of the three galaxies give these

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

values, from left to right: 7483, 8654, and 7618

km/s The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...

. The relatively high redshift for the center galaxy means that it is much farther away - about 65 million light years (20

megaparsec 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, and ...

s) behind the other two galaxies. Thus, the center galaxy is likely a background object. The NGC 5679 group was previously thought to be interacting gravitationally, however the newer Hubble image seems to confirm suspicions that the center galaxy is not interacting, as the galaxy arms are not distorted like typical

interacting galaxies Interacting galaxies (''colliding galaxies'') are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy disturbing the primary galaxy's spiral arms. An example of a ...

. One

supernova A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...

has been observed in NGC 5679: SN 1982D (type unknown, mag. 18).Transient Name Server entry for SN 1982D.
Retrieved 29 March 2023.

References

External links

* {{DEFAULTSORT:NGC 5679 Group

274 Year 274 ( CCLXXIV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Aurelianus and Capitolinus (or, less frequently, year 1027 ''Ab ...

Galaxy clusters 5679 Virgo (constellation)