Dynamics of Stellar Atmospheres

* 分析星光的详细特征，以确定1）组成恒星大气层的气体中看到的运动类型，2）恒星旋转的速度，3）恒星中产生的磁场类型，以及4）恒星在太空中移动的速度。 从这些测量中，我们了解了恒星中对流、脉动和旋转的物理过程，旋转如何与对流结合形成磁场，这些磁场如何在恒星表面造成黑点，以及恒星逃逸的质量如何与星星的磁场相互作用，作为制动器，减缓其旋转。 我的工作还包括多年来监测数十颗恒星，以观察它们的变化，特别是像我们的太阳所显示的11年磁周期这样的活动周期。 由于地球上的生命在很大程度上依赖于我们的太阳，因此将太阳理解为一颗星星并将其与其他恒星进行比较是很重要的。

***Detailed features in starlight are analyzed to determine 1) the kinds of motions seen in the gases comprising the atmospheres of stars, 2) how rapidly stars spin, 3) the kinds of magnetic fields generated in the stars, and 4) how fast stars move in space. From these measurements, we learn about the physical processes of convection, pulsation, and rotation in stars, how rotation combines with convection to make magnetic fields, how those magnetic fields cause dark spots on the surfaces of stars, and how mass escaping from stars interacts with the magnetic field of the star, acting as a brake, to slow its rotation. My work also involves monitoring dozens of stars over many years to see their changes, especially activity cycles like the 11-year magnetic cycle shown by our sun. Since life on earth depends critically on our sun, it is important to understand the sun as a star and to compare it to other stars.