|This article does not cite any references or sources. (May 2010)|
The galactic halo is an extended, roughly spherical component of a galaxy, which extends beyond the main, visible component. It can refer to any of several distinct components which share these properties:
The distinction between the halo and the main body of the galaxy is clearest in spiral galaxies, where the spherical shape contrasts with the flat disc. In an elliptical galaxy, there is no sharp transition between the body of the galaxy and the halo.
See also