The Andromeda Galaxy, also known as Messier 31 (M31), is a spiral galaxy located approximately 2.5 million light-years away from Earth in the constellation Andromeda. It is the closest galaxy to our Milky Way and is a member of the Local Group of galaxies that includes over 50 known galaxies.
The Andromeda Galaxy has a diameter of about 220,000 light-years, making it slightly larger than the Milky Way. It contains over a trillion stars, including many young blue stars, as well as older yellow and red stars. It also has a supermassive black hole at its center with a mass of about 100 million times that of the Sun.
The Andromeda Galaxy is visible to the naked eye in dark skies and has been known since ancient times. In the early 20th century, it was discovered that it was a separate galaxy from the Milky Way, which helped to expand our understanding of the universe. The Andromeda Galaxy is also an important target for astronomers studying the evolution of galaxies and the nature of dark matter, which is thought to be a major component of its mass.
, is a spiral galaxy located approximately 2.5 million light-years away from Earth in the constellation Andromeda.){kind=link}