Local Group

The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It is made up of two collections of galaxies shaped like a "dumbbell". One side has the Milky Way and its smaller galaxies, while the other side has the Andromeda Galaxy and its smaller galaxies. These two collections are about 800 kiloparsecs apart and are moving toward each other.

The Local Group has a total mass of about 2×10¹² solar masses and a diameter of 5.11 megaparsecs. It is part of the larger Local Volume and the Virgo Supercluster. The exact number of galaxies in the Local Group is not known because the Milky Way blocks some views, but we know of 134 galaxies within 1 megaparsec from the center. Most of these are small dwarf galaxies.

The two largest galaxies in the Local Group are the Andromeda Galaxy and the Milky Way. Both are spiral galaxies with masses of about 10¹² solar masses each. They each have many smaller galaxies orbiting them. The third-largest member is the Triangulum Galaxy, which is also a spiral galaxy. Other smaller galaxies in the Local Group include IC 10, IC 1613, and the Phoenix Dwarf Galaxy, among others.

History

The name "The Local Group" was first used by Edwin Hubble in his 1936 book The Realm of the Nebulae. He described it as a small group of galaxies that are isolated in space. Hubble listed several galaxies that belong to this group, including the Milky Way, where our Earth is located, and the Andromeda Galaxy, along with a few smaller ones.

Component galaxies

The Local Group is a collection of galaxies that includes our own Milky Way, where Earth is located. It has a special shape like two weights connected by a string, with the Milky Way and its smaller galaxies on one side, and the Andromeda Galaxy and its smaller galaxies on the other side.

These two groups of galaxies are moving towards each other. They are very far apart, about 800 kiloparsecs or 3 million light-years away from each other.

Structure

The Local Group is made up of the Milky Way, where our Earth is located, and the Andromeda Galaxy, along with many smaller galaxies. These galaxies are arranged in a shape like a dumbbell, with the Milky Way and Andromeda at each end.

Some interesting features include the Magellanic Stream, which is gas being pulled away from small galaxies near the Milky Way, and the Monoceros Ring, a ring of stars that may have come from another small galaxy. There are also other streams of stars and gas moving around these galaxies.

Main articles: Magellanic Stream, Monoceros Ring, stellar stream

Future

The galaxies in the Local Group, including the Milky Way where Earth is located, are slowly moving closer together due to gravity. Scientists believe that in many billions of years, these galaxies will come together to form one large galaxy. The joining of the Andromeda Galaxy and the Milky Way will be the most important part of this process. There is some discussion about exactly what kind of galaxy will form, but it will be a big change for the galaxies in our group.

Location

Main article: Laniakea Supercluster

The Local Group is a collection of galaxies that includes the Milky Way, the galaxy where our Earth is located. It looks like two groups of galaxies shaped like a dumbbell. One group has the Milky Way and its smaller galaxies, while the other group has the Andromeda Galaxy and its smaller galaxies. These two groups are moving towards each other.