Seyfert's Sextet is a group of galaxies about 190 million light-years away in the constellation Serpens. The group appears to contain six members, but one of the galaxies, NGC 6027d, is a background object and another "galaxy," NGC 6027e, is actually a part of the tail from galaxy NGC 6027. The gravitational interaction among these galaxies should continue for hundreds of millions of years. Ultimately, the galaxies will merge to form a single giant elliptical galaxy.
Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory. The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping is NGC 7320, which has extensive H II regions, identified as red blobs, where active star formation is occurring.
Édouard Jean-Marie Stephan was a French astronomer. His surname is sometimes spelled Stéphan in some literature, but this is apparently erroneous.
NGC 7320 is a spiral galaxy in Stephan's Quintet. However, it is not an actual member of the galaxy group, but a much closer line-of-sight galaxy at a distance of about 40 million light years, the same as the nearby NGC 7331. Other galaxies of Stephan's Quintet are some 300 million light-years distant.
Robert's Quartet is a compact galaxy group approximately 160 million light-years away in the constellation Phoenix. It is a family of four very different galaxies whose proximity to each other has caused the creation of about 200 star-forming regions and pulled out a stream of gas and dust 100,000 light years long. Its members are NGC 87, NGC 88, NGC 89 and NGC 92, discovered by John Herschel on the 30 September 1834.
NGC 7318 is a pair of colliding galaxies about 280 million light-years from Earth. They appear in the Constellation Pegasus and are members of Stephan's Quintet.
NGC 6027 is a lenticular galaxy discovered by Édouard Stephan in 1882 that is the brightest member of Seyfert's Sextet, a compact group of galaxies.
NGC 7319 is a highly distorted barred spiral galaxy that is a member of the compact Stephan's Quintet group located in the constellation Pegasus, some 311 megalight-years distant from the Milky Way. The galaxy's arms, dust and gas have been highly disturbed as a result of the interaction with the other members of the Quintet. Nearly all of the neutral hydrogen has been stripped from this galaxy, most likely as a result of a collision with NGC 7320c some 100 million years ago. A pair of long, parallel tidal tails extend southward from NGC 7319 in the direction of NGC 7320c, and is undergoing star formation.
NGC 7320c is a galaxy member of the Stephan's Quintet located in the constellation Pegasus.
NGC 7331 Group is a visual grouping of galaxies in the constellation Pegasus. Spiral galaxy NGC 7331 is a foreground galaxy in the same field as the collection, which is also called the Deer Lick Group. It contains four other members, affectionately referred to as the "fleas": the lenticular or unbarred spirals NGC 7335 and NGC 7336, the barred spiral galaxy NGC 7337 and the elliptical galaxy NGC 7340. These galaxies lie at distances of approximately 332, 365, 348 and 294 million light years, respectively. Although adjacent on the sky, this collection is not a galaxy group, as NGC 7331 itself is not gravitationally associated with the far more distant "fleas"; indeed, even they are separated by far more than the normal distances of a galaxy group.
NGC 5614 is an unbarred spiral galaxy in the constellation Boötes. It is the primary member of the Arp 178 triplet of interacting galaxies with NGC 5613 and NGC 5615.
NGC 5613 is a lenticular galaxy in the constellation Boötes. It is part of the Arp 178 set of interacting galaxies, with NGC 5615 and NGC 5614.
NGC 5545 is a spiral galaxy in the northern constellation of Boötes. It is interacting with the barred spiral galaxy NGC 5544.
NGC 22 is a spiral galaxy located in the Pegasus constellation. It was discovered in 1883 by Édouard Stephan.
NGC 70 is a spiral galaxy located in the constellation Andromeda. It was discovered on October 7, 1855, by R. J. Mitchell and was also observed on December 19, 1897 by Guillaume Bigourdan from France who described it as "extremely faint, very small, round, between 2 faint stars".
NGC 74 is a lenticular galaxy located in the Andromeda constellation. It was discovered on 7 October 1855 by Irish astronomer William Parsons.
NGC 453 is a triple star located in the constellation Pisces. It was discovered in 1881 by Édouard Stephan.
NGC 497 is a barred spiral galaxy approximately 336 million light-years away from Earth in the constellation of Cetus. It was discovered by French astronomer Édouard Stephan on November 6, 1882.
NGC 511, also occasionally referred to as PGC 5103 or UGC 936, is an elliptical galaxy in the constellation Pisces. It is located approximately 499 million light-years from the Solar System and was discovered on 26 October 1876 by French astronomer Édouard Stephan.
NGC 3868 is a lenticular galaxy located about 300 million light-years away in the constellation Leo. NGC 3868 was discovered by astronomer Édouard Stephan on March 23, 1884. It is a member of the Leo Cluster.
