The physics and chemistry of circumstellar envelopes of S-stars on the AGB
Conference contribution, 2008

Presented here are the preliminary results of a long-term study of S-stars on the AGB. S-stars are important as possible transition objects between oxygen-rich M-stars and carbon stars. The aim of the study is to compare results from our newly gathered observational database for the S-stars with those already obtained for the M- and carbon stars. We can thus follow the changes as the stars evolve along the AGB and more firmly establish the suggested M-MS-S-SC-C evolutionary sequence. It will also allow us to determine the relative importance of processes such as non-equilibrium chemistry, grain formation, and photodissociation in regulating the chemistry in circumstellar envelopes of AGB stars.

Author

S. Ramstedt

Fredrik Schöier

Chalmers, Department of Radio and Space Science, National Facility for Radio Astronomy

Hans Olofsson

Chalmers, Department of Radio and Space Science, National Facility for Radio Astronomy

in Proceedings of "Organic Matter in Space", Hong Kong feb. 18-22, 2008, IAU symposium 251, eds. S. Kwok, S. Sandfjord, Cambridge University Press

167-168

Subject Categories

Astronomy, Astrophysics and Cosmology

ISBN

9780521889827

More information

Created

10/7/2017