Evolution of oxygen-rich and carbon stars on the asymptotic giant branchThe transition from oxygen-rich (M) stars to S stars and then to C stars is examined using data on the chemical properties of the stars. The photospheric and circumstellar spectral characteristics of M and C stars are summarized. Consideration is given to the color distributions of carbon stars, visual carbon stars as transition objects, and radio observations of visual carbon stars. The chemical characteristics of S stars, the evolution of oxygen-rich stars on the AGB, and the transition between AGB stars and planetary nebulae are discussed. IRAS data are used to construct an evolutionary scenario for AGB stars, in which some mass-losing M stars remain oxygen rich, while others become carbon rich.
Document ID
19900044164
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kwok, Sun (Calgary Univ. Alberta Canada)
Chan, S. Josephine (Calgary, University Canada)
Volk, Kevine M. (NASA Ames Research Center Moffett Field, CA, United States)