asymptotic giant branch
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asymptotic giant branch(ass-im-tot -ik) See giant.
asymptotic giant branch[‚a‚sim¦täd·ik ‚jī·ənt ′branch]
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.