Glossary term: Dwarf Star

Description: "Dwarf star" is a synonym for a star on the so-called main sequence: Stars that fuse hydrogen to helium in their cores. Stars spend most of their "lives" as dwarf stars. Our Sun is a middle-aged dwarf. Typically, when astronomers refer to such main sequence stars, they include a reference to the color, such as "red dwarf" for the most common, low-mass dwarf stars, or "yellow dwarf" for stars like our Sun.

Caution: In astronomy, there are cases where the designation "dwarf" refers to objects that are not dwarf stars by this definition! Brown dwarfs are objects that have masses less than 8% of that of the Sun, and never start steady hydrogen burning in their cores – a kind of intermediate class of "substellar objects" between the mass range of stars and that of planets. White dwarfs, also called white dwarf stars, are the compact remnants of low to medium mass stars that have exhausted their nuclear fuel. When our Sun has reached the end of its stellar life, it will become a white dwarf.

Related Terms:

See this term in other languages

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".