SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION
SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION
复制标题
DOI：
10.1088/0004-6256/144/3/73
复制
发表时间：
2012-07
期刊：
影响因子：
--
通讯作者：
R. Wilson
中科院分区：
文献类型：
--
作者：
R. Wilson
最近的光度测量的几乎连续的时间覆盖范围是免费的大差距，妥协试图遵循恒星黑子的生长和衰变以及运动，从而激励提高模拟点的计算精度。由于巡天中的星星系统种类繁多，这种改进应适用于精确地包括近距离双星和旋转单星的所有主要现象的光/速度曲线模型。这里介绍的矢量分数面积（VFA）算法表示表面元素的位置向量的小集合，以便允许精确计算的圆三角形重叠球面几何。当通过VFA计算时，光斑在10，000分之一的水平上基本上不会在光变曲线中引入明显的散射。VFA已被纳入Wilson-Devinney光/速度曲线程序，并给出了所有的逻辑和数学，以方便进入其他此类程序。精确的点计算的优点包括改进了点运动和老化的统计，减少了计算时间（固有的精度放宽了网格精细度的要求），在数字中无噪声地说明了点的影响，并有助于防止在系外行星搜索中的误报，其中点可以近似地模仿凌日行星在不寻常的情况下。一个简单的斑点增长和衰减模板量化的时间分布，并给出其利用差分校正解决方案的具体情况。计算策略进行了讨论，整个过程进行了测试，通过模拟的解决方案的合成光变曲线数据，并描述了必要的模拟结果。一个有效的时间涂抹设施，高斯求积可以处理开普勒使命数据，在30分钟的时间箱。
The nearly continuous timewise coverage of recent photometric surveys is free of the large gaps that compromise attempts to follow starspot growth and decay as well as motions, thereby giving incentive to improve computational precision for modeled spots. Due to the wide variety of star systems in the surveys, such improvement should apply to light/velocity curve models that accurately include all the main phenomena of close binaries and rotating single stars. The vector fractional area (VFA) algorithm that is introduced here represents surface elements by small sets of position vectors so as to allow accurate computation of circle–triangle overlap by spherical geometry. When computed by VFA, spots introduce essentially no noticeable scatter in light curves at the level of one part in 10,000. VFA has been put into the Wilson–Devinney light/velocity curve program and all logic and mathematics are given so as to facilitate entry into other such programs. Advantages of precise spot computation include improved statistics of spot motions and aging, reduced computation time (intrinsic precision relaxes needs for grid fineness), noise-free illustration of spot effects in figures, and help in guarding against false positives in exoplanet searches, where spots could approximately mimic transiting planets in unusual circumstances. A simple spot growth and decay template quantifies time profiles, and specifics of its utilization in differential corrections solutions are given. Computational strategies are discussed, the overall process is tested in simulations via solutions of synthetic light curve data, and essential simulation results are described. An efficient time smearing facility by Gaussian quadrature can deal with Kepler mission data that are in 30 minute time bins.