Description: Supergiants are the largest and most luminous stars. They can be several hundred times larger than the Sun and many thousand times more luminous. They occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between −3 and −8. The temperature range of supergiant stars spans from about 3400 kelvins (K) to over 20,000 K. They are either massive stars or are in a very late phase of stellar evolution. Supergiant stars can be identified on the basis of their spectra, with distinctive lines sensitive to high luminosity and low surface gravity: these spectral lines are narrow compared to the width of lines in smaller stars. Typical examples of supergiant stars are Betelgeuse in Orion and the Cepheid variables.

Related Terms:

• Giant Star
• Red Supergiant
• Stellar Evolution
• 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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