文章基本信息

标题：Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses
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作者：Molly R.Kosiarek ; Ian J.M.Crossfield
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2020
卷号：159
期号：6
页码：3779-3787
DOI：10.3847/1538-3881/ab8d3a
语种：English
出版社：American Institute of Physics
摘要：Stellar activity remains a limiting factor in measuring precise planet parameters from radial velocity spectroscopy, not least in the search for Earth-mass planets orbiting in the habitable zones of Sun-like stars.One approach to mitigate stellar activity is to use combined analyses of both radial velocity and time-series photometry.We present an analysis of simultaneous disk-integrated photometry and radial velocity data of the Sun in order to determine the useful limits of a combined analysis.We find that simple periodogram or autocorrelation analysis of solar photometry give the correct rotation period <50% of the time.We therefore use a Gaussian process to investigate the time variability of solar photometry and to directly compare simultaneous photometry with radial velocity data.We find that the hyperparameter posteriors are relatively stable over 70 yr of solar photometry and the amplitude tracks the solar cycle.We observe good agreement between the hyperparameter posteriors for the simultaneous photometry and radial velocity data.Our primary conclusion is a recommendation to include an additional prior in Gaussian process fits to constrain the evolutionary timescale to be greater than the recurrence timescale (i.e., the rotation period) to recover more physically plausible and useful results.Our results indicate that such simultaneous monitoring may be a useful tool in enhancing the precision of radial velocity surveys.
关键词：Radial velocity;Stellar activity;Solar activity