Prominence activity on the rapidly rotating field star HD 197890
Prominence activity on the rapidly rotating field star HD 197890
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DOI：
10.1093/mnras/262.2.369
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发表时间：
1993-05
影响因子：
4.8
通讯作者：
R. Jeffries
中科院分区：
文献类型：
--
作者：
R. Jeffries
本文给出了最近发现的快速旋转的年轻场星星HD 197890的时间分辨Hα谱。观测结果包含快速的吸收和发射瞬变，这些瞬变在1小时量级的时间尺度上穿过从蓝色到红色的旋转加宽的Hα轮廓。吸收瞬变的行为与为另一个快速旋转的场星星AB Dor提出的模型是一致的，在该模型中，冷的物质云被困在星星表面上方的共转封闭磁性结构中，并将色球层Hα光子散射到视线之外。对这些云的径向加速度的测量表明，它们位于开普勒正转半径附近或之外
Time-resolved Hα spectra are presented of the recently discovered, rapidly rotating young field star HD 197890. The observations contain rapid absorption and emission transients that cross the rotationally broadened Hα profile from blue to red on time-scales of order 1 h. The behaviour of the absorption transients is consistent with models proposed for another rapidly rotating field star, AB Dor, in which cool clouds of material are trapped in corotating closed magnetic structures above the surface of the star and scatter chromospheric Hα photons out of the line of sight. Measurements of the radial acceleration of these clouds indicate that they are positioned at about or outside the Keplerian corotation radius