AI 中文总结
本研究基于II Peg的高分辨率光谱数据，通过分析Hα等谱线的多普勒位移特征，发现5个耀斑与6个潜在CME相关，耀斑-CME关联率约30%，还观测到两类日冕雨特征。
AI 中文摘要
恒星耀斑常伴随日珥爆发、日冕物质抛射（CME）及其他形式的等离子体运动。基于RS CVn型恒星II Pegasi（II Peg）的长期高分辨率光谱监测数据集，我们通过研究耀斑事件中Hα和Hβ谱线轮廓的不对称特征，搜寻恒星日珥爆发及潜在CME。我们观测到7个具有不对称光谱轮廓的光学耀斑，其Hα线释放的能量下限为10^33至10^34 erg。其中5个耀斑与6个潜在CME相关，这些CME通过色球谱线（尤其是Hα线）中的多普勒位移发射特征被识别。CME候选体的质量估计范围为10^19至10^20 g，动能约为10^33至10^34 erg；质量最大的CME候选体同时被Hα、Hβ和He I D3线记录。对于II Peg，耀斑-CME关联率约为30%。此外，Hα线轮廓中存在一些红移过量吸收特征，这些特征既出现在耀斑光谱中，也出现在非耀斑光谱中，可分别解释为耀斑驱动的日冕雨和宁静日冕雨的特征。
英文摘要
Stellar flares are frequently accompanied by prominence eruptions, coronal mass ejections (CMEs), and other forms of plasma motion. Based on the long-term high-resolution spectroscopic monitoring data set of the RS CVn-type star II Pegasi (II Peg), we search for stellar prominence eruptions and potential CMEs by investigating asymmetric signatures in the H$_α$ and H$_β$ line profiles during the flare events. We observed seven optical flares with asymmetric spectral profiles, releasing low limit energies of $10^{33}$--$10^{34}$ erg in the H$_α$ line. Five of these flares were associated with six potential CMEs, identified through the Doppler-shifted emission signatures in the chromospheric line profiles, particularly the H$_α$ line. The mass estimates for the CME candidates range from $10^{19}$ to $10^{20}$ g, while the kinetic energies are calculated to be around $10^{33}$--$10^{34}$ erg. The most massive CME candidate was simultaneously recorded in the H$_α$, H$_β$, and He I D$_{3}$ lines. For II Peg, the possible flare-CME association rate is about 30\%. There were also some redshifted excess absorption signatures in the H$_α$ line profiles. These signatures could not only be observed in the flaring spectra but also in the spectra without flare, which could be interpreted as features resulting from flare-driven coronal rain and quiescent rain, respectively.
Journal ref2025ApJ...991...54C
