文章基本信息

标题：Hunt for Starspots in HARPS Spectra of G and K Stars
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作者：Brett M.Morris ; H.Jens Hoeijmakers ; Daniel Kitzmann 等
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：160
期号：1
页码：1-7
DOI：10.3847/1538-3881/ab9365
语种：English
出版社：American Institute of Physics
摘要：We present a method for detecting starspots on cool stars using the cross-correlation function (CCF) of high-resolution molecular spectral templates applied to archival high-resolution spectra of G and K stars observed with the High Accuracy Radial Velocity Planet Searcher (HARPS)/HARPS-N. We report nondetections of starspots on the Sun even when the Sun was spotted, the solar twin 18 Scorpii, and the very spotted Sun-like star HAT-P-11, suggesting that Sun-like starspot distributions will be invisible to the CCF technique, and should not produce molecular absorption signals that might be confused for signatures of exoplanet atmospheres. We detect strong TiO absorption in the T Tauri K-dwarfs LkCa 4 and AA Tau, consistent with significant coverage by cool regions. We show that despite the nondetections, the technique is sensitive to relatively small spot coverages on M dwarfs and large starspot areas on Sun-like stars.
关键词：Stellar activity (1580);High resolution spectroscopy (2096);Starspots (1572);Stellar magnetic fields (1610)