Infall and Outflow Activities in the Be star FY CMa     

Hui-Lai Cao National Astronomical Observatories  Chinese Academy of Sciences  Beijing CAS-PKU Joint Beijing Astrophysics Center  Peking University  Beijing 《中国天文和天体物理学报》2001,1(6):514-524

Unusual activity of outflow mass motion connected with infail events was recorded for the B0.5 IVe star FY CMa in February 1987 from both archival IUE spectrograms of cixcumstellar Nv resonance hnes and optical spectra of Hα and He I λ5876A emission lines which showed inverse P Cygni-type profiles. We estimate the mass loss rate using ultraviolet SiIvresonance lines with expanding atmosphere modeling calculations, and describe how the radial pressure performs the dominant role in accelerating the stellar wind. We attempt to give a qualitative explanation for the activity observed for FY CMa in terms of circumstellar matter raining down to the star.  相似文献