Description: A subgiant is a star which lies in between the main sequence and the giant branch on a Hertzsprung–Russell diagram. These are mostly stars that have ended hydrogen fusion in their cores and are evolving to becoming giant stars. Some of these subgiants pulsate, making them variable stars. Cepheid variables are an example of a type of pulsating subgiant stars.

Related Terms:

• Cepheid Variable
• Giant Star
• Hertzsprung–Russell (HR) Diagram
• Hydrogen Fusion
• Main Sequence
• Stellar Evolution
• Variable Star
• Luminosity Class

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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