Astrophysics (index)about

red giant

(reddish, giant late stage of stellar evolution)

A red giant results from a main sequence star of small stellar mass (.3 to 8 solar masses), which grows large, luminous, and reddish, with a surface temperature below 5000K. Its spectral class at this point is K-type star, M-type star, or S-type star. Radius grows often to more than an AU, so that the volume of the Sun in such a state would include Earth's orbit.

The star is a red giant for a period at the end of its main sequence lifetime, when the stellar core has fused as much hydrogen as it can and cools and contracts. The layer of gas surrounding the core gets closer to the center, heats and begins fusing, expanding greatly because of the heat.

The core finally collapses and heats, resulting in a helium flash and/or white dwarf.


(star type,stellar evolution)

Referenced by:
asymptotic giant branch (AGB)
binary star
Canis Major Dwarf Galaxy
cosmic dust
evolutionary track
giant star
horizontal branch (HB)
helium flash
H-R diagram (HRD)
low mass star
M-type star (M)
post main sequence star
red-giant branch (RGB)
Schönberg-Chandrasekhar limit
stellar evolution
symbiotic binary
Thorne-Żytkow object (TZO)
Wilson-Bappu effect