Context. Tidal disruption events (TDEs) are rare transients that provide important insights into the physics of galactic nuclei. A recently identified feature in their optical light curves is the presence of early bump-like structures (precursors) that appear before the onset of the main flare or during its rise. Aims. We aim to build and study the first sample of precursor TDEs in order to improve our understanding of these features, which could be key to revealing the origin of the optical emission in TDEs. Methods. We compiled all known precursor TDEs from the literature, searched for additional candidates, and analyzed them as a sample. Results. We find that precursor TDEs predominantly fall within the repeating TDE, fast TDE, and TDE in active galactic nucleus (AGN) subclasses. We reveal a positive correlation between the occurrence time of the precursors relative to the main peak and the central black hole mass. Conclusions. We suggest that the precursors appear due to interactions between the incoming stellar debris and the disk or leftover material from an earlier disruption (repeating and fast TDEs) or a stable pre-existing disk (TDEs in AGNs). Precursors are therefore potentially key signatures of repeating partial TDEs in previously quiescent galaxies.
Repeating flares, X-ray outbursts and delayed infrared emission: A comprehensive compilation of optical tidal disruption events
Institute of Astrophysics, FORTH（FORTH天体物理研究所）；Department of Physics, University of Crete（克里特大学物理系）；NASA Marshall Space Flight Center（美国宇航局马歇尔太空飞行中心）；Institutt for Fysikk, Norwegian University of Science and Technology（挪威科技大学物理系）；Instituto de Astronomía, Universidad Nacional Autónoma de México Campus Ensenada（墨西哥国立自治大学恩塞纳达天文研究所）；Kavli Institute for Particle Astrophysics and Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Astronomical Observatory, University of Warsaw（华沙大学天文台）；Astrophysics Division, National Centre for Nuclear Research（国家核研究中心天体物理部）；Astronomical Institute, University of Wrocław（弗罗茨瓦夫大学天文研究所）
Repeated Tidal Interactions between Stars and Supermassive Black Holes: Mass Transfer, Stability, and Implications for Repeating Partial Tidal Disruption Events
Back from the dead: AT2019aalc as a candidate repeating TDE in an AGN
Ruhr Astroparticle and Plasma Physics Center (RAPP Center)（鲁尔天体物理与等离子体物理中心）；Leiden Observatory, Leiden University（莱顿天文台，莱顿大学）；Deutsches Elektronen-Synchrotron (DESY)（德国电子同步辐射中心）；Institut fur Physik, Humboldt-Universität zu Berlin（柏林洪堡大学物理研究所）；Division of Physics, Mathematics, and Astronomy, California Institute of Technology（加州理工学院物理、数学和天文学系）；University of Maryland, Department of Astronomy（马里兰大学天文学系）；NASA Goddard Space Flight Center, Astrophysics Science Division（美国宇航局戈达德太空飞行中心天体物理学科学部）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/GSFC空间科学与技术研究探索中心）
Rapid onset of a Comptonisation zone in the repeating tidal disruption event XMMSL2 J140446.9-251135
Telespazio UK for ESA（ESA英国泰莱斯帕齐奥）；Schmidt Sciences（施密特科学）；Space Telescope Science Institute（太空望远镜科学研究所）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；University of Arizona（亚利桑那大学）；Max-Planck-Institut für extraterrestrische Physik（马普地外物理研究所）；University of Hertfordshire（赫特福德大学）；University of Oxford（牛津大学）；Centro de Astrobiología (CAB), CSIC-INTA（CSIC-INTA天体生物学中心）；ESA（欧洲空间局）；SERCO for ESA（ESA塞科服务）
Stellar Stripping and Disruption in Disks around Supermassive Black Hole Binaries: Repeating nuclear transients prior to LISA events
Space Telescope Science Institute（太空望远镜科学研究所）；Johns Hopkins University（约翰斯·霍普金斯大学）；Niels Bohr International Academy, Niels Bohr Institute（尼尔斯·玻尔国际学院，尼尔斯·玻尔研究所）；Chungbuk National University（忠北国立大学）；Aoyama Gakuin University（青山学院大学）；University of Zurich（苏黎世大学）
Are most detected tidal disruption events partial?
School of Physics and Astronomy, Monash University（莫纳什大学物理与天文学院）；IPAG, Univ. Grenoble Alpes, CNRS（格勒诺布尔阿尔卑斯大学CNRS IPAG研究所）；School of Physics, University of Melbourne（墨尔本大学物理学院）；Department of Astronomy and Astrophysics, University of California, Santa Cruz（加州大学圣克鲁兹分校天文学与天体物理学系）
VLASS tidal disruption events with optical flares II: discovery of two TDEs with intermediate width Balmer emission lines and connections to the ambiguous extreme coronal line emitters
A Disappearing Act: Constraints From "Missing" Flares of Repeating Partial TDE Candidates
University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；NSF-Simons AI Institute for the Sky (SkAI)（美国国家科学基金会西蒙斯天空人工智能研究所）；Northwestern University（西北大学）；Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)（天体物理学跨学科探索与研究中心）；Institute for Advanced Study in Physics, Zhejiang University（浙江大学高等物理研究院）；Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）
A Formation Crisis of Repeating Partial Tidal Disruption Events
Tsung-Dao Lee Institute, Shanghai Jiao-Tong University（上海交大李政道研究所）；School of Physics & Astronomy, Shanghai Jiao-Tong University（上海交通大学物理与天文学院）；Cornell University（康奈尔大学）
Bridging Roche Lobe Overflow and micro-TDEs: The Runaway Evolution of Eccentric Mass Transfer in Star-Black Hole Binaries
Tsung-Dao Lee Institute, Shanghai Jiao-Tong University（上海交大李政道研究所）；Department of Physics, College of Sciences, Shanghai University（上海大学理学院）；Department of Astronomy, Center for Astrophysics and Planetary Science, Cornell University（康奈尔大学天文学系天体物理学与行星科学中心）
Tidal disruption of stellar binaries as a pathway to exotic transients
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）；SECIHTI–Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo（米却肯州圣尼古拉斯伊达尔戈大学SECIHTI物理与数学研究所）；Facultad de Ciencias Físico Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo（米却肯州圣尼古拉斯伊达尔戈大学物理数学科学学院）
A tidal disruption event in a quasar at redshift 7.19
University of Toronto（多伦多大学）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓普天文学与天体物理研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）
AT2019aalc: An obscured tidal disruption event candidate in an active galactic nucleus revealed by its first flare?
College of Physics and Electronic Engineering, Northwest Normal University（西北师范大学物理与电子工程学院）；School of Physical Science and Technology, Guangxi University（广西大学物理科学与技术学院）
Can tidal disruption event models reliably measure black hole masses?
Queen’s University Belfast（贝尔法斯特女王大学）；University of Birmingham（伯明翰大学）；University of Cambridge（剑桥大学）；The Observatories of the Carnegie Institute for Science（卡内基科学研究所天文台）；University of California, Davis（加州大学戴维斯分校）；University of California, Berkeley（加州大学伯克利分校）；University of Maryland, College Park（马里兰大学帕克分校）
Ultra-long Gamma-ray Bursts from Micro-Tidal Disruption Events: The Case of GRB 250702B
The Open University of Israel（以色列开放大学）；Astrophysics Research Center of the Open University (ARCO)（以色列开放大学天体物理研究中心）；Department of Physics, The George Washington University（乔治华盛顿大学物理系）；Technion - Israel Institute of Technology（以色列理工学院）
GRB 250702B被解释为微潮汐破坏事件，通过三种路径解释其超长持续、高能和快速变化的伽马射线特征。
