An elliptical galaxy is a galaxy having an about ellipsoidal shape as well as a smooth, very featureless brightness profile. They range in shape from very spherical to highly flat & in size from hundreds of millions to over trillion stars. They can be the result of galaxies colliding.
Elliptical galaxies are of the main classes of galaxy originally described by American astronomer Edwin Hubble in his 1936 work The Realm of the Nebulae,[1] along with spiral & lenticular galaxies. Elliptical galaxies are (together with lenticular galaxies) also called "early-type" galaxies (ETG), due to their location in the Hubble sequence.
Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium & minimal star formation activity. They are surrounded by giant numbers of globular clusters. Elliptical galaxies are believed to make up about 1015% of galaxies in the local Universe[2] but are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters[3] & are less common in the early Universe.
Elliptical galaxies are of the main classes of galaxy originally described by American astronomer Edwin Hubble in his 1936 work The Realm of the Nebulae,[1] along with spiral & lenticular galaxies. Elliptical galaxies are (together with lenticular galaxies) also called "early-type" galaxies (ETG), due to their location in the Hubble sequence.
Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium & minimal star formation activity. They are surrounded by giant numbers of globular clusters. Elliptical galaxies are believed to make up about 1015% of galaxies in the local Universe[2] but are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters[3] & are less common in the early Universe.