Stellar pulsation: (I) analysis of stability of envelope |
| |
Authors: | Zhi-Yao Yu |
| |
Institution: | (1) Shanghai Observatory, 80 Nandan Road, 200030 Shanghai, China |
| |
Abstract: | The life-time of the star on AGB is approximately 6 × 104 yr. We divide it into front half and back half of AGB (including to optical Mira variable and OH/IR star) according to their evolution character. The observations show that the star has non-pulsation, but constant mass loss rate ( 5 × 10–7
M
yr–1) on front half of AGB. Its circumstellar envelope is formed. When the star has pulsation on back half of AGB, its mass loss rate is relative with time, and increases gradually. In this time the star is on the stage of optical Mira variable. When the mass loss rate reaches the value of 3 × 10–6
M
yr–1, the star evoluted from the stage of optical variable into the stage of radio bright OH/IR star. On the end of AGB the mass loss rate reaches 10–4
M
yr–1. (Band and Habing 1983, Hermen and Habing 1985). |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|