Elliptical galaxy

An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work The Realm of the Nebulae, along with spiral and lenticular galaxies. Elliptical (E) galaxies are, together with lenticular galaxies (S0) with their large-scale disks, and ES galaxies with their intermediate scale disks, a subset of the "early-type" galaxy population. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity, and they tend to be surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10–15% of galaxies in the Virgo Supercluster, and they are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters. Elliptical galaxies range in size from dwarf ellipticals with tens of millions of stars, to supergiants of over one hundred trillion stars that dominate their galaxy clusters. Originally, Edwin Hubble hypothesized that elliptical galaxies evolved into spiral galaxies, which was later discovered to be false, although the accretion of gas and smaller galaxies may build a disk around a pre-existing ellipsoidal structure. Stars found inside of elliptical galaxies are on average much older than stars found in spiral galaxies. 3C 244.1 M49 M59 M60 (NGC 4649) M87 (NGC 4486), whose supermassive black hole is the first black hole to be imaged by the Event Horizon Telescope M89 M105 (NGC 3379) ESO 383-76, one of the largest galaxies known. IC 1101, the central galaxy of Abell 2029 Hercules A, supergiant elliptical galaxy Maffei 1, the closest giant elliptical galaxy CGCG 049-033, known for having the longest galactic jet discovered Centaurus A (NGC 5128), an elliptical/lenticular radio galaxy with peculiar morphology and unusual dust lanes NeVe 1, the source of the Ophiuchus Supercluster eruption, the most powerful astronomical event known Elliptical galaxies are characterized by several properties that make them distinct from other classes of galaxy.