Including the Milky Way's satellite Sagittarius elliptical galaxy and denoted "dE" of "dIrr" in the Hubble scheme, for 10 points, identify these types of galaxies so called because they have very low mass and luminosity.
NGC 6822, the first definitely determined extragalactic object, belongs to the irregular subclass of these objects. Shaplow and Baade's studies of the Sculptor constellation led to the discovery of the first spheroidal example of these objects, which are characterized by extremely low metallicity. Examples of these types of objects include the Ursa Minor galaxy, and NGC 205, an Andromeda companion. Twenty-two of the 41 local group galaxies are of this type, which also includes the Small Magellanic Cloud, which is labeled as one of these despite being brighter than most of them. Including the Milky Way's satellite Sagittarius elliptical galaxy and denoted "dE" of "dIrr" in the Hubble scheme, for 10 points, identify these types of galaxies so called because they have very low mass and luminosity.
NGC 6822, the first definitely determined extragalactic object, belongs to the irregular subclass of these objects.
dwarf galaxies