Local Group

- Describe the Local Group of galaxies
- Recall the names of some galaxies in the Local Group, including the Large and Small Magellanic Clouds, Andromeda Galaxy (M31) and the Triangulum Galaxy (M33)
- Demonstrate an understanding that galaxies are grouped in larger clusters and superclusters.

Galaxies are not always solitary bodies. Very frequently they are grouped together and sometimes interact or even collide. There are twenty galaxies in our Local Group.

The Milky Way is actually converging with a smaller galaxy, the Sagittarius Dwarf galaxy. In several million years' time, the larger Andromeda galaxy (M31) will converge with the Milky Way and form a larger galaxy.

Some of these groups are grouped again. The Milky Way Group is part of a larger group again called a cluster. We are in the Virgo Supercluster. Isn’t that nice!

We also have companion galaxies orbiting very close to the Milky Way in the form of Magellanic Clouds, after which was named after the explorer Magellan when he ventured into the Southern Hemisphere. The nearest, the Large Magellanic Cloud orbits just 170,000 light years away from us. The Small Magellanic Cloud is slightly further, while the Andromeda Galaxy, the largest galaxy in the Local Group is 2 million light years away. Other notable galaxies include the Triangulum Galaxy.

The Milky Way lies roughly in the middle of the Local Group.

People once thought that the Earth was at the centre of the Solar System before the heliocentric theory was proven. Once more was known about gGalaxies, people wondered if the Milky Way was the centre of the Universe.

 

Animation New Window

Milky Way animation Milky Way

Image New Window

Links New Window

SEDS Local Group

High Energy Astrophysics Science Archive Research Center The Local Group

Astronomy Picture of the Day Clusters of Galaxies

Questions

  • What is the Local Group of galaxies?
  • Name some galaxies in the Local Group?
  • What kinds of groups have been observed?