由恆星色球層活動引起的閃焰是低質量恆星上的重要現象,它對於系外行星的適居性有重要的影響。較少發生超級閃焰活動的恆星可以為生命發展提供較佳的環境,而M型星既長壽又在銀河系中大量存在,是發展系外生命的理想地點,因此其閃焰活動對探索系外生命的研究相當重要。 我們收集了克卜勒望遠鏡的光變資料以及LAMOST望遠鏡與雲南天文台、興隆觀測站兩米級望遠鏡的光譜資料,用以檢測閃焰事件以及計算色球層活躍程度。 在論文的第一部份,我們發現晚型恆星的色球活動比早型恆星高,而自轉較慢的恆星通常也較不活躍,此結果與前人研究相符。在有行星環繞的恆星中,我們沒有偵測到閃焰事件,其色球層活躍程度也與不產生閃焰的恆星相似,此一結果與前人在具超級閃焰的恆星光變曲線上找不到行星的掩星紀錄的結果相互印證。 論文第二部分中,M型雙星系統的大型閃焰(能量為10$^{34}$ ergs以上)較超亮閃焰M型星少,但總體閃焰發生率約為一般有閃焰的M型單星的十倍。藉由統計各雙星系統公轉相位上的閃焰數量,我們發現在部分雙星系統中,質量較小的伴星可能貢獻更多閃焰事件。;Flare activity is an important phenomena caused by the chromosphere activity in late-type stars. It′s also important to the habitability of the exoplanets. Stars with less frequent superflares provide the better environments for the life development, especially for the M-type stars, whose longevity and abundance make them the good environments of habitable exoplanets.
We collected the light curve data from Kepler telescope and spectral data from LAMOST, YNAO, and Xing-Long 2-m level telescopes for detecting flare events and measuring the chromospheric active levels of late-type stars with exoplanets or in binary systems. In the first part of this thesis, the 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. Also, the later type stars are more active than earlier type stars.
In the second part of this thesis, 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.