Core Viewpoint - The research team from Peking University has detected a new type of millisecond radio burst originating from the magnetic field of stellar sunspot regions using the "China Sky Eye" (FAST), filling a gap in understanding small-scale magnetic fields of exoplanetary stars and significantly contributing to the study of space weather beyond the solar system [1][2]. Group 1 - The solar magnetic field drives solar activity, which typically originates from localized strong magnetic field regions such as sunspots [1]. - Similar magnetic activity phenomena exist on other late-type stars, with some stars (like active M-type stars) exhibiting more intense and frequent magnetic activities than the Sun, significantly affecting the habitability of nearby planets [1]. - Traditional methods for measuring stellar magnetic fields have primarily provided large-scale global magnetic field information, lacking the ability to discern small-scale magnetic structures in stellar sunspot regions [1]. Group 2 - The high sensitivity radio observations from "China Sky Eye" offer a new complementary approach to optical methods for detecting and studying sunspots [1]. - By detecting radio signals emitted from the localized magnetic field structures above stellar sunspots, the research team can constrain the size of the sunspots and understand the strength and structure of the coronal magnetic field above them, accurately characterizing the properties of stellar sunspots [1]. - The research team is also utilizing FAST to explore young solar-type stars, brown dwarfs, and stellar-planet interaction processes, which will further expand understanding of stellar magnetic activities and their driven exoplanetary space weather phenomena, providing important insights for the search for habitable exoplanets [2].

田晖告诉科技日报记者，该研究取得成功的关键在于FAST的高灵敏度和高分辨率。过去恒星射电观测 时间分辨率大多只有小时或分钟量级，而FAST把观测时间分辨率提升到了"亚毫秒"级，能捕捉恒星射 电辐射的细微瞬变，目前世界上几乎没有其他设备能与之媲美。 （科技日报） 图为本次观测结果示意图，右上方为观测到的射电频谱。受访者供图 近日，以北京大学地球与空间科学学院田晖教授和博士生张佳乐为主的研究团队利用"中国天眼"FAST （500米口径球面射电望远镜），首次探测到来自恒星黑子区域的毫秒级射电暴信号，为直接探测恒星 小尺度磁场、揭示恒星磁活动的起源提供了全新的观测手段。相关论文于北京时间10月18日发表于国际 学术期刊《科学进展》。 长期以来，直接测量恒星黑子区磁场是困扰学术界的难题。该发现说明恒星黑子区域的磁活动能将电子 加速到极高能量，这些电子在磁场中做回旋运动，产生独特的射电辐射。捕捉这些射电信号，就可以直 接分析恒星表面小尺度的磁场结构。它为研究恒星磁活动的起源、理解恒星复杂的磁场结构提供了全新 方法。 ...

Core Viewpoint - The research team led by Professor Tian Hui from Peking University has successfully detected millisecond-level radio burst signals from stellar sunspot regions using the FAST telescope, providing a new observational method for studying stellar magnetic activity and its origins [2]. Group 1: Research Findings - The detection of radio signals indicates that magnetic activity in stellar sunspot regions can accelerate electrons to high energies, which then produce unique radio emissions as they spiral in the magnetic field [2]. - This breakthrough allows for direct analysis of the small-scale magnetic field structure on stellar surfaces, enhancing the understanding of complex stellar magnetic fields [2]. Group 2: Technological Advancements - The success of this research is attributed to the high sensitivity and resolution of the FAST telescope, which has improved the time resolution of stellar radio observations to the "sub-millisecond" level, enabling the capture of minute variations in stellar radio emissions [3]. - Currently, there are very few devices worldwide that can match the capabilities of FAST in this regard [3].