Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.
The Whirlpool Galaxy, also known as Messier 51a (M51a) or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is about 31 million light-years (9.5 Mpc) away from Earth and 76,900 ly (23,580 pc) in diameter.
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 51 is a lenticular galaxy in the constellation Andromeda. It has a diameter of 90,000 light-years. The galaxy was discovered on September 7, 1885 by Lewis Swift, who described it as "Pretty faint, pretty small, round, brighter middle."
NGC 936 is a barred lenticular galaxy in the constellation Cetus. It is at a distance of about 60 million light-years away from Earth. Its nucleus and prominent bar have high surface brightness. Because of the shape of the prominent bar, the nucleus and the ring of stars at the end of the barrel, the galaxy has been compared with the shape of a TIE fighter, from the Star Wars universe, and thus NGC 936 has been named Darth Vader’s Galaxy or Darth Vader’s Starfighter. By measuring the radial velocity of the disc, Kormendy found in 1986 that the disc is stable, which is the reason why it is so smooth.
NGC 131 is a spiral galaxy that was discovered on September 25, 1834, by John Herschel. This galaxy belongs in the NGC 134 group of galaxies: NGC 115, NGC 148, NGC 150, PGC 2000, IC 1555, and PGC 2044.
NGC 169 is a barred spiral galaxy located in the constellation Andromeda. It was discovered on September 18, 1857 by R. J. Mitchell.
NGC 191 is a spiral galaxy located in the constellation Cetus. It was discovered on November 28, 1785 by William Herschel.
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 364 is a barred lenticular galaxy in the constellation Cetus. It was discovered on September 2, 1864 by Albert Marth. It was described by Dreyer as "very faint, very small."
NGC 375 is an elliptical galaxy located in the constellation Pisces. It was discovered on September 12, 1784 by William Herschel. It was described by Dreyer as "pretty faint, small, round, brighter middle." Along with galaxies NGC 379, NGC 380, NGC 382, NGC 383, NGC 384, NGC 385, NGC 386, NGC 387 and NGC 388, NGC 375 forms a galaxy cluster called Arp 331.
NGC 380 is an elliptical galaxy located in the constellation Pisces. It was discovered on September 12, 1784 by William Herschel. It was described by Dreyer as "pretty faint, small, round, suddenly brighter middle." Along with galaxies NGC 375, NGC 379, NGC 382, NGC 383, NGC 384, NGC 385, NGC 386, NGC 387 and NGC 388, NGC 380 forms a galaxy cluster called Arp 331.
NGC 2782 is a peculiar spiral galaxy that formed after a galaxy merger in the constellation Lynx. The galaxy lies 75 million light years away from Earth, which means, given its apparent dimensions, that NGC 2782 is approximately 100,000 light years across. NGC 2782 has an active galactic nucleus and it is a starburst and a type 1 Seyfert galaxy. NGC 2782 is mentioned in the Atlas of Peculiar Galaxies in the category galaxies with adjacent loops.
NGC 679 is an elliptical or a lenticular galaxy located 210 million light-years away in the constellation Andromeda. The galaxy was discovered by astronomer William Herschel on September 13, 1784 and is a member of Abell 262.
NGC 1380 is a lenticular galaxy located in the constellation Fornax. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 1380 is about 85,000 light years across. It was discovered by James Dunlop on September 2, 1826. It is a member of the Fornax Cluster.
NGC 710 is a spiral galaxy located 260 million light-years away in the constellation Andromeda. It was discovered by the Irish engineer and astronomer Bindon Blood Stoney on October 28, 1850 and is a member of the galaxy cluster Abell 262.
NGC 753 is a spiral galaxy located 220 million light-years away in the constellation Andromeda. The galaxy was discovered by astronomer by Heinrich d'Arrest on September 16, 1865 and is a member of Abell 262.
NGC 759 is an elliptical galaxy located 230 million light-years away in the constellation Andromeda. NGC 759 was discovered by astronomer by Heinrich d'Arrest on September 17, 1865. It is a member of Abell 262.
IC 1459 is an elliptical galaxy located in the constellation Grus. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that IC 1459 is about 130,000 light-years across. It was discovered by Edward Emerson Barnard in 1892.
NGC 543 is an elliptical galaxy in the constellation Cetus. It is estimated to be 239 million light years from the Milky Way and has a diameter of approximately 40,000 ly. NGC 543 was discovered by the German-Danish astronomer Heinrich Louis d'Arrest. It is a member of the galaxy cluster Abell 194.
