NGC 5679 (also popularly known as Arp 274) is an impressive triplet of galaxies located approximately 400 million light-years from Earth, in the direction of the constellation Virgo (theskylive.com). Although at first glance they appear to be violently colliding, astronomical studies suggest that they may be at slightly different distances and only partially overlapping in our line of sight.
NGC 5670, otherwise known as Arp 274, with the individual galaxies labled.
Components of the Triplet
The cluster extends for approximately 200,000 light-years and is composed of three distinct galaxies cataloged by Halton Arp's Atlas of Peculiar Galaxies.
Central Galaxy (NGC 5679B / MCG+1-37-35): It is the largest component of the group. This is a spiral galaxy (possibly barred) that exhibits its shape and arms virtually intact, reinforcing the theory that there is no strong destructive gravitational interaction between them.
Right Galaxy (NGC 5679A / MCG+1-37-34): A spiral galaxy classified as having a high starburst rate. Its spiral arms are filled with bright blue clusters full of young stars.
Left Galaxy (NGC 5679C): The smallest and most compact of the three. Despite its small size, it also shows strong evidence of new star formation activity.
Key Astronomical Features:
Historical Discovery: The main structure was originally discovered by the German-British astronomer William Herschel on May 12, 1793.
Star Nursery: High-resolution images captured by the NASA/ESA Hubble Space Telescope reveal bright blue knots (young stars) scattered throughout the galactic arms and pink nebulae illuminated by star birth.
Foreground Stars: Near the galaxy on the right, two very bright stars can be seen. They are not part of the triplet; they are foreground stars belonging to our own galaxy, the Milky Way.
Speed
Redshift measurements of the three galaxies give these radial velocity values, from left to right: 7483, 8654, and 7618 km/s. The relatively high redshift for the center galaxy means that it is much farther away - about 65 million light years (20 megaparsecs) 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.
Supernovae
One supernova has been observed in NGC 5679: SN 1982D (type unknown, mag. 18) was discovered by Halton Arp and Jack W. Sulentic on 23 March 1982.
Characteristics of the NGC 5679 Group
Key Highlights
Partial Optical Illusion: Although listed as an interacting system by Halton Arp, velocity data suggests the central galaxy might lie at a slightly different distance, making the triplet a line-of-sight overlap rather than a violent merger.
Active Star Nurseries: Hubble Space Telescope imagery shows that the vibrant blue knots in the spiral arms are massive clusters of young stars, all less than 10 million years old.
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