NGC 4631 is a barred spiral galaxy in the constellation Canes Venatici. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. Because this nearby galaxy is seen edge-on from Earth, professional astronomers observe this galaxy to better understand the gas and stars located outside the plane of the galaxy.
NGC 5195 is a dwarf galaxy that is interacting with the Whirlpool Galaxy. Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most famous interacting galaxy pairs.
NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.
NGC 3227 is an intermediate spiral galaxy that is interacting with the dwarf elliptical galaxy NGC 3226. The two galaxies are one of several examples of a spiral with a dwarf elliptical companion that are listed in the Atlas of Peculiar Galaxies. Both galaxies may be found in the constellation Leo. It is a member of the NGC 3227 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.
NGC 3226 is a dwarf elliptical galaxy that is interacting with the spiral galaxy NGC 3227. The two galaxies are one of several examples of a spiral with a dwarf elliptical companion that are listed in the Atlas of Peculiar Galaxies. Both galaxies may be found in the constellation Leo. It is a member of the NGC 3227 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.
NGC 4088 is an intermediate spiral galaxy in the constellation Ursa Major. The galaxy forms a physical pair with NGC 4085, which is located 11′ away.
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 primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among galaxies.
The NGC 4631 Group is a poorly defined group of galaxies, about 25 million light-years from Earth in the Coma Berenices and Canes Venatici constellations.
NGC 4618 is a distorted barred dwarf galaxy in the constellation Canes Venatici. The galaxy is formally classified as a Sm galaxy, which means that its structure vaguely resembles the structure of spiral galaxies. The galaxy is sometimes referred to as a Magellanic spiral because of its resemblance to the Magellanic clouds.
Arp 240 is a pair of interacting spiral galaxies located in the constellation Virgo. The two galaxies are listed together as Arp 240 in the Atlas of Peculiar Galaxies. The galaxy on the right is known as NGC 5257, while the galaxy on the left is known as NGC 5258. Both galaxies are distorted by the gravitational interaction, and both are connected by a tidal bridge, as can be seen in images of these galaxies.
NGC 2535 is an unbarred spiral galaxy exhibiting a weak inner ring structure around the nucleus in the constellation Cancer that is interacting with NGC 2536. The interaction has warped the disk and spiral arms of NGC 2535, producing an elongated structure, visible at ultraviolet wavelengths, that contain many bright, recently formed blue star clusters in addition to enhanced star forming regions around the galaxy center. The two galaxies are listed together in the Atlas of Peculiar Galaxies as an example of a spiral galaxy with a high surface brightness companion.
NGC 2608 is a barred spiral galaxy located 93 million light-years away in the constellation Cancer. It is 62,000 light-years across, and about 60% of the width of the Milky Way. It is considered a grand design spiral galaxy and is classified as SB(s)b, meaning that the galaxy's arms wind moderately around the prominent central bar.
NGC 3432 is a spiral galaxy that can be found in the constellation Leo Minor. It is seen edge-on and with its current interaction with UGC 5983, a near by dwarf galaxy, it features tidal filaments and intense star formation, which is why it was listed in Halton Arp's Atlas of Peculiar Galaxies.
NGC 1023 is a barred lenticular galaxy, a member of the NGC 1023 group of galaxies in the Local Supercluster. Distance measurements vary from 9.3 to 19.7 million parsecs (30 to 64 million light-years). The supermassive black hole at the core has a mass of (4.4±0.5)×107 M☉. The black hole was discovered by analyzing the dynamics of the galaxy.
NGC 5566 is a barred spiral galaxy in the constellation Virgo, which is approximately 66 million light years away from Earth. The galaxy is the biggest in the constellation Virgo, stretching nearly 150,000 light years in diameter. The galaxy NGC 5566 was discovered on 30 April 1786 by the German-British astronomer William Herschel. It is included in Halton Arp's Atlas of Peculiar Galaxies. It is a member of the NGC 5566 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
Arp 7 is a spiral galaxy in the constellation Hydra. Redshift-independent measurements of its distance vary widely, from 5.9 Mpc to 83.7 Mpc. Its morphological classification is SB(rs)bc, meaning it is a barred spiral galaxy with some ring-like structure.
NGC 1614 is the New General Catalogue identifier for a spiral galaxy in the equatorial constellation of Eridanus. It was discovered on December 29, 1885 by American astronomer Lewis Swift, who described it in a shorthand notation as: pretty faint, small, round, a little brighter middle. The nebula was then catalogued by Danish-Irish astronomer J. L. E. Drayer in 1888. When direct photography became available, it was noted that this galaxy displayed some conspicuous peculiarities. American astronomer Halton Arp included it in his 1966 Atlas of Peculiar Galaxies. In 1971, Swiss astronomer Fritz Zwicky described it as a "blue post-eruptive galaxy, compact patchy core, spiral plumes, long blue jet SSW".
NGC 169 is a barred spiral galaxy located in the constellation Andromeda. It was discovered on September 18, 1857 by R. J. Mitchell.
NGC 341 is a spiral galaxy in the constellation Cetus. It was discovered on October 21, 1881 by Édouard Stephan. It was described by Dreyer as "faint, pretty large, round, a little brighter middle, mottled but not resolved." It has a companion galaxy, PGC 3627, which is sometimes called NGC 341B. For this, reason, it has been included in Halton Arp's Atlas of Peculiar Galaxies.
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.
