论文标题
宽带精确光曲线的分析点模型中的信息内容。 ii。斑点分布和寿命，全球和差分旋转
The Information Content in Analytic Spot Models of Broadband Precision Light Curves. II. Spot Distributions and Lifetimes, Global and Differential Rotation
论文作者
论文摘要
随着太空精确光度法任务的出现，星线光曲线的数量和质量大大增加了。本文介绍了大量的星形模型及其所得的光曲线至：1）更好地确定传达有用的物理信息的光曲线指标和方法，2）了解如何从物理星点分布到产生的光曲线的转换的基础脱落性，掩盖了该信息。我们在几个倾斜度上探索相对活跃的恒星的模型，同时改变（黑暗）斑点的数量，位置和时间的随机斑点分布，生长和衰减的时间表以及差异旋转。我们检查了个体强度下降和整体光曲线的绝对和差异变化的行为，并证明了复杂的点分布和行为如何导致光曲线通常仅显示一个或两个旋转的一两个下降。不幸的是，简单化的“一个或两个斑点”或“主动经度”描述或光曲线的建模通常会引起高度误导。我们还表明，简短的“活动周期”很容易仅仅是由于随机过程。 事实证明，消除斑点寿命和差异旋转的竞争效果非常困难，但是在大多数情况下，斑点寿命是两者中更具影响力的。许多技术仅在斑点生存以进行许多旋转时才尝试约会。这些包括用于现场寿命和全局和差分旋转的期间图的自相关降解。除非斑点在许多旋转中生存，否则几乎不可能仅凭光曲线准确地推断出差异旋转。不幸的是，太阳和太阳能型星是其年龄或更大的情况。需要进一步的工作以增加对光曲线推断的信心。
With the advent of space-based precision photometry missions the quantity and quality of starspot light curves has greatly increased. This paper presents a large number of starspot models and their resulting light curves to: 1) better determine light curve metrics and methods that convey useful physical information, 2) understand how the underlying degeneracies of the translation from physical starspot distributions to the resulting light curves obscure that information. We explore models of relatively active stars at several inclinations while varying the number of (dark) spots, random spot distributions in position and time, timescales of growth and decay, and differential rotation. We examine the behavior of absolute and differential variations of individual intensity dips and overall light curves, and demonstrate how complex spot distributions and behaviors result in light curves that typically exhibit only one or two dips per rotation. Unfortunately simplistic "one or two spot" or "active longitude" descriptions or modeling of light curves can often be highly misleading. We also show that short "activity cycles" can easily be simply due to random processes. It turns out to be quite difficult to disentangle the competing effects of spot lifetime and differential rotation, but under most circumstances spot lifetime is the more influential of the two. Many of the techniques tried to date only work when spots live for many rotations. These include autocorrelation degradation for spot lifetimes and periodograms for both global and differential rotation. Differential rotation may be nearly impossible to accurately infer from light curves alone unless spots live for many rotations. The Sun and solar-type stars its age or older are unfortunately the most difficult type of case. Further work is needed to have increased confidence in light curve inferences.
