An elliptical galaxy is a galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile. They range in shape from nearly spherical to highly flattened and in size from hundreds of millions to over one trillion stars.
Elliptical galaxies are one of the three main classes of galaxy originally described by Edwin Hubble in his 1936 work “The Realm of the Nebulae”, along with spiral and lenticular galaxies.
Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity. They are surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10-15% of galaxies in the local Universe but are the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters and are less common in the early Universe.
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