A model of slingshot prominences in rapidly rotating stars
A model of slingshot prominences in rapidly rotating stars
复制标题
快速旋转恒星中的弹弓日珥模型
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
J. Ferreira
中科院分区：
文献类型：
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作者：
J. Ferreira
本文研究了快速旋转恒星中双折射平衡模型的稳定性。日珥是一个轴对称的赤道电流片，它嵌入在无质量的、完全导电的日冕等离子体中。作用在日珥上的引力、离心力和洛仑兹力之间存在一个平衡。伯恩斯坦等人的能量方法，Lepeltier & Aly提出的形式，用于获得充分的稳定性条件。使用现有的观测值的质量，尺寸和日冕位置的双折射，我们发现，几百高斯的表面场需要保持它们在一个稳定的平衡。在稳定平衡模型中存在的自由磁能足以供给中等规模的耀斑，但可能不足以供给能量很大的耀斑。
我们讨论的问题是什么使恒星的折射率如此不同，从他们的太阳同行，是什么让他们被检测到。我们还研究了共转半径在其形成中的作用。
We study the stability of an equilibrium model of prominences in rapidly rotating stars. A prominence is represented by an axisymmetric equatorial current sheet embedded in a massless and perfectly conducting coronal plasma. There is an equilibrium between gravity, centrifugal force and Lorentz force acting on the prominence. The energy method of Bernstein et al., in the form presented by Lepeltier & Aly, is used to derive sufficient stability conditions. Using existing observational values for the masses, dimensions and coronal locations of the prominences, we find that surface fields of a few hundred Gauss are required to hold them in a stable equilibrium. The free magnetic energy present in stable equilibrium models is sufficient to feed medium-sized flares but probably not the very energetic ones.
We discuss the question of what makes stellar prominences so different from their solar counterparts and what allows them to be detected. We also examine the role of the corotation radius in their formation.