凌日系外行星巡天卫星（TESS）观测到的附近年轻类太阳恒星黑子与耀斑的时间分辨联系
Time-Resolved Connection between Starspots and Flares in Nearby Young Solar-type Stars Observed by TESS
浏览论文内容
中文总结 AI 辅助
研究利用TESS数据探究三颗年轻类太阳恒星磁活动，自动检测耀斑等得出相关数据，发现耀斑频率和黑子面积跨扇区变化，二者呈正相关，支持超级耀斑由磁能驱动，还发现黑子面积与自转周期可能有关，拓展了太阳磁活动机制。
中文摘要 AI 辅助
超级耀斑是恒星表面能量为10^33 - 10^36尔格的高能爆发，远超典型太阳耀斑。此前研究虽表明这些事件由大黑子储存的磁能驱动，但单个恒星黑子面积与耀斑活动的详细时间分辨关系仍不明晰。本文利用凌日系外行星巡天卫星（TESS）约7年的光度数据，研究了三颗代表性年轻类太阳恒星（御夫座EK、杜鹃座DS Tucanae A和武仙座V889）的磁活动时间演化。自动检测恒星耀斑并得出每个约27天的TESS扇区的耀斑频率、黑子面积和自转周期。结果发现，各扇区耀斑频率和黑子面积变化显著，未发现类似活动周期的模式。三颗目标恒星的黑子面积与耀斑发生频率呈正相关，幂律依赖关系一致。这支持了年轻类太阳恒星上的超级耀斑由大黑子储存的磁能驱动的物理图景，且能量释放率随总储存磁能变化。此外，对御夫座EK的分析发现黑子面积可能与自转周期有关，这可能表明大黑子优先在中纬度形成。这些发现表明，为太阳建立的磁活动机制可延伸到年轻活跃恒星上观测到的极端磁活动。
英文摘要
Superflares are energetic explosions on stellar surface with energies of 10^33-10^36 erg, significantly exceeding those of typical solar flares. While previous studies have suggested that these events are driven by magnetic energy stored in large starspots, the detailed time-resolved relationship between starspot area and flare activity on individual stars has remained unclear. In this paper, we investigate the time evolution of magnetic activity on three representative young solar-type stars (EK Draconis, DS Tucanae A, and V889 Herculis) using $\sim$7 years of photometric data from the Transiting Exoplanet Survey Satellite (TESS). We automatically detected stellar flares and derived the flare frequency, starspot area, and rotational period for each TESS sector covering ~27 days. As a result, we found that the flare frequency and starspot area vary significantly across sectors, although we could not identify any activity-cycle-like pattern. There is a positive correlation between the starspot area and flare occurrence frequency for all three targets and the power-law dependence is consistent among the stars. This result supports the physical picture that superflares on young solar-type stars are powered by magnetic energy stored in large starspots, analogous to solar flares, and that the energy release rate changes as the total stored magnetic energy varies. Furthermore, from the analysis of EK Draconis, we find a possible dependence of starspot area on rotation period, which may suggest that large starspots preferentially form at mid-latitudes. These findings demonstrate that the magnetic activity mechanisms established for the Sun extend to the extreme magnetic activity observed on young active stars.
