主講人：Li-Ching Huang (黃立晴)
時間：2020-11-6 12:20 (星期五) / 地點：B101
Abstract: Flare activity is an important phenomena caused by the chromosphere activity in late-type stars. We collected the light curve data from Kepler telescope and spectral data from ground-based telescopes for detecting flare events and measuring the chromospheric active levels of late-type stars with exoplanets or in binary systems. Our result agrees with the previous studies that slow rotators are less active than fast rotators and the stars with exoplanets tend to have less flare activity and lower chromospheric activity levels. M-type eclipsing binaries (EBs) show less flare events with large flares (energy release 10^34 ergs) than the hyperflaring M dwarfs, but their cumulative flare frequency factor is 10 times higher than the flaring single M dwarfs. The flare timing also shows that the secondary stars might be the major flare producers in some EB systems. Flare activity is also important to the habitability of the exoplanets. Stars with less frequent superflares provide better environments for life development, especially for the M-type stars, whose longevity and abundance make them good environments for habitable exoplanets. Kepler-442 is a K-type main-sequence star with an earth size exoplanet (2.3 M_earth) in the habitable zone. Flare events are detected on this star, which is different from our result that exoplanet systems rarely show flare activity.