Surface imaging of HD 199178 (V1794 Cygni)

被引:46
作者
Hackman, T
Jetsu, L
Tuominen, I
机构
[1] Univ Helsinki Observ, Helsinki 00014, Finland
[2] Univ Oulu, Astron Div, Oulu 90014, Finland
关键词
stars; activity; imaging; late-type; starspots; individual; HD; 199178;
D O I
10.1051/0004-6361:20010682
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present surface temperature maps for the FK Comae-type star HD 199178 (V1794 Cygni) calculated from high resolution spectra obtained in 1994 and 1995. The spot pattern evolves, but all maps reveal a large cool spot remaining nearly at the same high latitude. The main spot is 1200-1600 K cooler than the mean surface temperature. The observed slightly at bottomed absorption lines would usually be interpreted as evidence for a large cool polar spot. We argue that antisolar surface differential rotation offers a better explanation for the box like shape of the line profiles. However, we do not find conclusive evidence for antisolar differential rotation and note that there are still other possible explanations for the slightly at bottomed line profiles.
引用
收藏
页码:171 / 181
页数:11
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