近日，中国科学技术大学王义博团队报道了千次切割终结恒星：AT2023uqm的失控周期性喷发。2026年8月19日，《科学通报》杂志发表了这一成果。

围绕超大质量黑洞作束缚轨道运动的恒星可能会经历重复的部分潮汐撕裂事件（rpTDEs），产生周期性耀发。虽然已提出数个候选体，但这些事件的确切证实仍未实现。研究组报告了AT2023uqm的发现，这是一个核区暂现源，已表现出至少五次周期性光学耀发，使其成为继ASASSN-14ko之后第二个经确认的周期性案例。独特之处在于，AT2023uqm的耀发能量呈近乎指数增长——这是一种“失控”现象，标志着恒星正在逐步瓦解。

这一行为与低质量主序星或演化后巨星发生rpTDEs的预期一致。对最近两次耀发的多波段观测和光谱分析进一步支持其rpTDE的物理解释。引人注目的是，每次耀发均呈现相似的双峰结构，可能源于双峰质量回落率，或每轨道周期内发生两次离散的碰撞。峰值间隔与轨道周期的极端比值引起了关于被瓦解恒星可能为巨星的关注，这可以通过未来质量损失演化与低质量主序星相区分。研究组的分析展示了rpTDEs在探测被瓦解恒星性质以及潮汐撕裂物理过程方面的潜力，但目前仍受限于人们对这些事件的认知。AT2023uqm是迄今为止最有说服力的rpTDE候选体，为这类现象的建模和理解提供了关键框架。

附：英文原文

Title: A star’s death by a thousand cuts: the runaway periodic eruptions of AT2023uqm

Author: anonymous

Issue&Volume: 2026/08/19

Abstract: Stars on bound orbits around a supermassive black hole may undergo repeating partial tidal disruption events (rpTDEs), producing periodic flares. While several candidates have been suggested, definitive confirmation of these events remains elusive. We report the discovery of AT2023uqm, a nuclear transient that has exhibited at least five periodic optical flares, making it only the second confirmed case of periodicity after ASASSN-14ko. Uniquely, the flares from AT2023uqm show a nearly exponential increase in energy — a “runaway” phenomenon signaling the star’s progressive destruction. This behavior is consistent with rpTDEs of low-mass main-sequence stars or evolved giant stars. Multiwavelength observations and spectroscopic analysis of the two most recent flares reinforce its interpretation as an rpTDE. Intriguingly, each flare displays a similar double-peaked structure, potentially originating from a double-peaked mass fallback rate or two discrete collisions per orbit. The extreme ratio of peak separation to orbital period draws attention to the possibility of a giant star being disrupted, which could be distinguished from a low-mass main-sequence star by its future mass-loss evolution. Our analysis demonstrates the power of rpTDEs to probe the properties of disrupted stars and the physical processes of tidal disruption, though it is currently limited by our knowledge of these events. AT2023uqm emerges as the most compelling rpTDE thus far, serving as a crucial framework for modeling and understanding these phenomena.

DOI: 10.1016/j.scib.2026.08.025

Source: https://www.sciencedirect.com/science/article/pii/S2095927326009114