asymptotic giant branch


asymptotic giant branch

(ass-im-tot -ik) See giant.

asymptotic giant branch

[‚a‚sim¦täd·ik ‚jī·ənt ′branch] (astronomy) A grouping of stars on the Hertzsprung-Russell diagram that is roughly asymptotic to the giant branch; it represents a later stage in giant-star evolution in which hydrogen-fusing and helium-fusing shells surround a core in which both hydrogen fusion and helium fusion are exhausted. Abbreviated AGB.