Glossary term: Horizontal Branch

Description: Stars that are fusing helium to carbon in their cores are called horizontal branch stars. The name arises because these stars lie along a horizontal branch in the Hertzsprung–Russell diagram, displaying a range of "surface" temperatures (effective temperatures) but nearly constant luminosity. These are stars that have evolved beyond the red giant phase with variable amounts of mass (outer layers) lost. Main sequence stars with mass up to eight times the mass of the Sun can go through this evolutionary phase.

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".