Dwarf elliptical galaxy

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Dwarf elliptical galaxies are elliptical galaxies that are much smaller than others, classified as dE. They are quite common, and are usually companions to other galaxies. There are at least two dE dwarf ellipticals in orbit around the Andromeda galaxy.

Examples of Dwarf Ellipticals:

NGC 147 (DDO 3) - type dE5 pec in Cassiopeia
SagDIG (Sagittarius Dwarf Irregular Galaxy) - type IB(s)m V in Sagittarius
NGC 6822 (Barnard's Galaxy) - type IB(s)m IV-V in Sagittarius
Aquarius Dwarf (DDO 210) - type Im V in Aquarius
IC 5152 - type IAB(s)m IV in Indus
Pegasus Dwarf Irregular Galaxy (DDO 216) - type Irr in Pegasus

A subtype of dwarf ellipticals is called a dwarf spheroidal galaxy. It is now thought that these are basically the same kind of galaxy, but are just viewed from a different angle.

Most evidence indicates that most small "ellipticals" do not have properties similar to those of large ellipticals. Instead, they are probably related to irregular galaxies. Therefore, many astronomers have taken to using dwarf spheroidal galaxy to refer to this type.