Glossary term: Galactic Halo
Description: The galactic halo is a roughly spherical distribution of stars, gas, and dark matter which extends above, below, and beyond the disk of the Milky Way. Stars in the halo are older and have a lower metal content than most of the stars in the disk of the Milky Way. In the region around the Sun only a few percent of the stars are from the halo. Globular clusters of stars are also found in the galactic halo.
An invisible halo of dark matter also extends through and around the Milky Way, containing most of the Galaxy's mass.
Most other galaxies also have haloes.
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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
