An expanding circumstellar cloud of Zeta Aurigae |
| |
Authors: | Mamoru Saitō |
| |
Affiliation: | (1) Tokyo Astronomical Observatory, University of Tokyo, Mitaka, Tokyo, Japan |
| |
Abstract: | Strong absorption satellite lines of CaI 6572 were found on spectrograms taken on three successive days just after the fourth contact of the 1971–72 eclipse of Zeta Aurigae. The radial velocities of the satellite lines are –88 km s–1, –74 km s–1, and –180 km–1, respectively, relative to the K-type primary star (K4 Ib). These absorptions should be due to a circumstellar cloud in which the column density of neutral calcium atoms is 1×1017 cm–2 and the turbulent velocities come to 20–50 km s–1. It is suggested that the cloud may be formed by the rocket-effect of the Lyman quanta of the B-type component (B6 V). We estimate the density in the cloud to be 2×1011 atoms cm–3 fors=10RK and 2×1010 atoms cm–3 fors=102RK, wheres denotes the distance of the cloud from the K star andRK the K star's radius. The mass loss rate of the K-type component is also estimated to be about 10–7M yr–1, assuming that the expansion of the K star occurs isotropically. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|