SiC grains and evolution of carbon stars.
Abstract
A set of 32 carbon stars envelopes in a large range of spectral types has been modelled. The models were performed with two kinds of grains : SiC and amorphous carbon. Contrary to our previous study each kind of grain may be formed now at different distances from the central star. Correlations between SiC/A.C. ratio abundance and extinction opacity as well as SiC/A.C. ratio and period of luminosity were found. These correlations may indicate that the quantity of SiC grains relative to amorphous carbon grains decreases with carbon star evolution. A modification in SiC feature with increasing extinction opacity seems also to be connected to this evolution.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1994
- Bibcode:
- 1994A&A...291..831L
- Keywords:
-
- Abundance;
- Carbon Stars;
- Extinction;
- Silicon Carbides;
- Stellar Envelopes;
- Stellar Evolution;
- Stellar Models;
- Absorptance;
- Data Reduction;
- Dust;
- Local Thermodynamic Equilibrium;
- Radiative Transfer;
- Spectrum Analysis;
- Astrophysics;
- STARS: CARBON;
- CIRCUMSTELLAR MATTER;
- RADIATIVE TRANSFER;
- DUST;
- EXTINCTION