TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy
Stein R, Carney J, Ward C, Margutti R, Hall XJ, Sfaradi I, Andreoni I, Charalampopoulos P, Chornock R, Gezari S, Mo G, Yao Y, Anumarlapudi A, Bellm EC, Bloom JS, Busmann M, Caiazzo I, Cenko SB, Graham MJ, Groom SL, Gruen D, Hammerstein E, Kaiser BC, Kasliwal MM, O’Connor B, Palmese A, Purdum J, Rastinejad JC, Riddle R, Rusholme B, Sollerman J, Somalwar JJ, Veilleux S. 2026. TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy. The Astrophysical Journal Letters. 1006(2), L57.
Download
Journal Article
| Published
| English
Scopus indexed
Author
Stein, Robert;
Carney, Jonathan;
Ward, Charlotte;
Margutti, Raffaella;
Hall, Xander J.;
Sfaradi, Itai;
Andreoni, Igor;
Charalampopoulos, Panos;
Chornock, Ryan;
Gezari, Suvi;
Mo, Geoffrey;
Yao, Yuhan
All
All
Department
Abstract
Tidal disruption events (TDEs) have traditionally been discovered in optical sky surveys through targeted searches of nuclear transients. However, it is expected that some TDEs will occur outside the galaxy nucleus, arising from wandering black holes (BHs) originating in galaxy mergers. Here, we present observations of TDE 2025abcr, the first optical TDE discovered in the outskirts of a host galaxy. The TDE was identified by a custom “off-nuclear” implementation of the machine learning classifier tdescore, which classifies new ZTF transients based on their lightcurves. Follow-up observations confirm that TDE 2025abcr is a TDE-H+He, occurring 9
5 (9.3 kpc projected distance) from the nucleus of a massive galaxy (M⋆ = 1011.18±0.03M⊙) with a central BH mass of 108.82±0.65M⊙. TDE 2025abcr itself was likely disrupted by a much lighter BH (106.09±0.53M⊙, as estimated with peak luminosity scaling relations). The BH was either dynamically ejected from the nucleus or lies at the center of a very faint tidally stripped dwarf galaxy undergoing a minor merger. Late-time observations of TDE 2025abcr could confirm the origin of this apparent “wandering” BH. The rate of highly offset (≳3 kpc) TDEs can be constrained to <10% of the nuclear TDE rate, but our discovery implies that many dozens of similar sources will be detected by the Vera C. Rubin Observatory each year with resolvable offsets.
Publishing Year
Date Published
2026-07-27
Journal Title
The Astrophysical Journal Letters
Publisher
IOP Publishing
Acknowledgement
We thank Muryel Guolo, Dan Perley, and Carl Rodriguez for the fruitful discussions about off-nuclear TDEs.
Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the ZTF project. ZTF is supported by the National Science Foundation under award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan, and the German Center for Astrophysics (DZA), Germany. Operations are conducted by Caltech’s Optical Observatory (COO), Caltech/IPAC, and the University of Washington at Seattle, USA.
SED Machine is based upon work supported by the National Science Foundation under grant No. 1106171.
The Gordon and Betty Moore Foundation, through both the Data-Driven Investigator Program and a dedicated grant, provided critical funding for SkyPortal.
These results were obtained with the use of LDT, owned and operated by the Lowell Observatory
Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 nonprofit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
A major upgrade of the Kast spectrograph on the Shane 3 m telescope at Lick Observatory, led by Brad Holden, was made possible through gifts from the Heising-Simons Foundation, William and Marina Kast, and the University of California Observatories. Research at Lick Observatory is partially supported by a generous gift from Google.
This work is based (in part) on observations made with NOT, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias under NOT programmes 72-504. The NOT data presented here were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOT.
This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester.
This paper contains data obtained at the Wendelstein Observatory of the Ludwig-Maximilians University Munich. We thank Christoph Ries for carrying out the observations. Funded in part by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC-2094/2—390783311.
The national facility capability for SkyMapper has been funded through ARC LIEF grant LE130100104 from the Australian Research Council, awarded to the University of Sydney, the Australian National University, Swinburne University of Technology, the University of Queensland, the University of Western Australia, the University of Melbourne, Curtin University of Technology, Monash University, and the Australian Astronomical Observatory. SkyMapper is owned and operated by The Australian National University’s Research School of Astronomy and Astrophysics. The survey data were processed and provided by the SkyMapper Team at ANU. The SkyMapper node of the All-Sky Virtual Observatory (ASVO) is hosted at the National Computational Infrastructure (NCI). Development and support of the SkyMapper node of the ASVO has been funded in part by Astronomy Australia Limited (AAL) and the Australian Government through the Commonwealth’s Education Investment Fund (EIF) and National Collaborative Research Infrastructure Strategy (NCRIS), particularly the National eResearch Collaboration Tools and Resources (NeCTAR) and the Australian National Data Service Projects (ANDS).
The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We thank the NRAO for carrying out the Karl G. Jansky VLA observation.
Note Added - Shortly before this work was accepted, we became aware of a later preprint by K. Patra et al. (2026). The work reaches many similar conclusions to our own, and presents additional JWST data of TDE 2025abcr. We also thank the authors for highlighting a typo on an earlier version of this manuscript, with the projected offset incorrectly given as 10.3 kpc rather than 9.3 kpc.
Facilities: PO:1.2m - Palomar Observatory's 1.2 meter Samuel Oschin Telescope (ZTF), Hale - Palomar Observatory's 5.1m Hale Telescope (protoCerberus), Keck:I - KECK I Telescope (LRIS), LDT - (DeVeney, LMI), NOT - Nordic Optical Telescope (ALFOSC), PO:1.5m - Palomar Observatory's 1.5 meter Telescope (SEDM), SOAR - The Southern Astrophysical Research Telescope (Goodman), Swift - Swift Gamma-Ray Burst Mission (XRT, UVOT) - , VLA - Very Large Array, WO:2m - (3KK).
Software: astroquery (B. D. Johnson et al. 2021), emcee (D. Foreman-Mackey et al. 2013), HEASoft, galsynthspec (R. D. Stein 2025), mirar (R. D. Stein et al. 2025), prospector (B. D. Johnson et al. 2021), SCAMP (E. Bertin 2006), scarlet (P. Melchior et al. 2018), Source Extractor (E. Bertin & S. Arnouts 1996), swifttools, tdescore (R. Stein et al. 2024), uvotredux (R. D. Stein & J. Carney 2025).
Volume
1006
Issue
2
Article Number
L57
ISSN
eISSN
IST-REx-ID
Cite this
Stein R, Carney J, Ward C, et al. TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy. The Astrophysical Journal Letters. 2026;1006(2). doi:10.3847/2041-8213/ae77f3
Stein, R., Carney, J., Ward, C., Margutti, R., Hall, X. J., Sfaradi, I., … Veilleux, S. (2026). TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy. The Astrophysical Journal Letters. IOP Publishing. https://doi.org/10.3847/2041-8213/ae77f3
Stein, Robert, Jonathan Carney, Charlotte Ward, Raffaella Margutti, Xander J. Hall, Itai Sfaradi, Igor Andreoni, et al. “TDE 2025abcr: A Tidal Disruption Event in the Outskirts of a Massive Galaxy.” The Astrophysical Journal Letters. IOP Publishing, 2026. https://doi.org/10.3847/2041-8213/ae77f3.
R. Stein et al., “TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy,” The Astrophysical Journal Letters, vol. 1006, no. 2. IOP Publishing, 2026.
Stein R, Carney J, Ward C, Margutti R, Hall XJ, Sfaradi I, Andreoni I, Charalampopoulos P, Chornock R, Gezari S, Mo G, Yao Y, Anumarlapudi A, Bellm EC, Bloom JS, Busmann M, Caiazzo I, Cenko SB, Graham MJ, Groom SL, Gruen D, Hammerstein E, Kaiser BC, Kasliwal MM, O’Connor B, Palmese A, Purdum J, Rastinejad JC, Riddle R, Rusholme B, Sollerman J, Somalwar JJ, Veilleux S. 2026. TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy. The Astrophysical Journal Letters. 1006(2), L57.
Stein, Robert, et al. “TDE 2025abcr: A Tidal Disruption Event in the Outskirts of a Massive Galaxy.” The Astrophysical Journal Letters, vol. 1006, no. 2, L57, IOP Publishing, 2026, doi:10.3847/2041-8213/ae77f3.
All files available under the following license(s):
Creative Commons Attribution 4.0 International Public License (CC-BY 4.0):
Main File(s)
File Name
Access Level
Open Access
Date Uploaded
2026-08-11
MD5 Checksum
42b983f18497bb644f422709de7dc68c
arXiv 
Google Scholar