Abstract The Kepler and TESS missions have unveiled that cool stars frequently host exoplanets. These exoplanets are subject to environmental changes due to flares and associated coronal mass ejections (CMEs) that may change their atmospheric dynamics and chemistry. However, substantial observational evidence of CMEs from G-M dwarfs remains scarce. Recent efforts to detect stellar CMEs have predominantly utilized methodologies derived from solar observations. Notably successful approaches have been the detection of Doppler shifts and coronal dimming associated with stellar flares, which are interpreted as strong indicators of stellar CMEs. Although the detection of type-II radio bursts remains elusive, candidates for type-IV radio bursts have been recently reported. Numerous indicators have been tested; however, each methodology presents its own set of issues and limitations, and a definitive answer remains elusive. This paper reviews the recent progress and proposes several future directions in CME observations of active stars.
Kosuke Namekata (Sun,) studied this question.