---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '22675'
abstract:
- lang: eng
  text: "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\r\n5 (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."
acknowledgement: "We thank Muryel Guolo, Dan Perley, and Carl Rodriguez for the fruitful
  discussions about off-nuclear TDEs.\r\n\r\nBased 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.\r\n\r\nSED Machine is based upon work supported by the National Science Foundation
  under grant No. 1106171.\r\n\r\nThe Gordon and Betty Moore Foundation, through both
  the Data-Driven Investigator Program and a dedicated grant, provided critical funding
  for SkyPortal.\r\n\r\nThese results were obtained with the use of LDT, owned and
  operated by the Lowell Observatory\r\n\r\nSome 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.\r\n\r\nA 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.\r\n\r\nThis 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.\r\n\r\nThis work made use of data supplied
  by the UK Swift Science Data Centre at the University of Leicester.\r\n\r\nThis
  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.\r\n\r\nThe 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).\r\n\r\nThe 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.\r\n\r\nNote 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.\r\n\r\nFacilities: 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).\r\n\r\nSoftware:
  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)."
article_number: L57
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Robert
  full_name: Stein, Robert
  last_name: Stein
- first_name: Jonathan
  full_name: Carney, Jonathan
  last_name: Carney
- first_name: Charlotte
  full_name: Ward, Charlotte
  last_name: Ward
- first_name: Raffaella
  full_name: Margutti, Raffaella
  last_name: Margutti
- first_name: Xander J.
  full_name: Hall, Xander J.
  last_name: Hall
- first_name: Itai
  full_name: Sfaradi, Itai
  last_name: Sfaradi
- first_name: Igor
  full_name: Andreoni, Igor
  last_name: Andreoni
- first_name: Panos
  full_name: Charalampopoulos, Panos
  last_name: Charalampopoulos
- first_name: Ryan
  full_name: Chornock, Ryan
  last_name: Chornock
- first_name: Suvi
  full_name: Gezari, Suvi
  last_name: Gezari
- first_name: Geoffrey
  full_name: Mo, Geoffrey
  last_name: Mo
- first_name: Yuhan
  full_name: Yao, Yuhan
  last_name: Yao
- first_name: Akash
  full_name: Anumarlapudi, Akash
  last_name: Anumarlapudi
- first_name: Eric C.
  full_name: Bellm, Eric C.
  last_name: Bellm
- first_name: Joshua S.
  full_name: Bloom, Joshua S.
  last_name: Bloom
- first_name: Malte
  full_name: Busmann, Malte
  last_name: Busmann
- first_name: Ilaria
  full_name: Caiazzo, Ilaria
  id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
  last_name: Caiazzo
  orcid: 0000-0002-4770-5388
- first_name: S. Bradley
  full_name: Cenko, S. Bradley
  last_name: Cenko
- first_name: Matthew J.
  full_name: Graham, Matthew J.
  last_name: Graham
- first_name: Steven L.
  full_name: Groom, Steven L.
  last_name: Groom
- first_name: Daniel
  full_name: Gruen, Daniel
  last_name: Gruen
- first_name: Erica
  full_name: Hammerstein, Erica
  last_name: Hammerstein
- first_name: Benjamin C.
  full_name: Kaiser, Benjamin C.
  last_name: Kaiser
- first_name: Mansi M.
  full_name: Kasliwal, Mansi M.
  last_name: Kasliwal
- first_name: Brendan
  full_name: O’Connor, Brendan
  last_name: O’Connor
- first_name: Antonella
  full_name: Palmese, Antonella
  last_name: Palmese
- first_name: Josiah
  full_name: Purdum, Josiah
  last_name: Purdum
- first_name: Jillian C.
  full_name: Rastinejad, Jillian C.
  last_name: Rastinejad
- first_name: Reed
  full_name: Riddle, Reed
  last_name: Riddle
- first_name: Ben
  full_name: Rusholme, Ben
  last_name: Rusholme
- first_name: Jesper
  full_name: Sollerman, Jesper
  last_name: Sollerman
- first_name: Jean J.
  full_name: Somalwar, Jean J.
  last_name: Somalwar
- first_name: Sylvain
  full_name: Veilleux, Sylvain
  last_name: Veilleux
citation:
  ama: 'Stein R, Carney J, Ward C, et al. TDE 2025abcr: A tidal disruption event in
    the outskirts of a massive galaxy. <i>The Astrophysical Journal Letters</i>. 2026;1006(2).
    doi:<a href="https://doi.org/10.3847/2041-8213/ae77f3">10.3847/2041-8213/ae77f3</a>'
  apa: '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. <i>The Astrophysical Journal Letters</i>. IOP Publishing. <a
    href="https://doi.org/10.3847/2041-8213/ae77f3">https://doi.org/10.3847/2041-8213/ae77f3</a>'
  chicago: '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.” <i>The Astrophysical Journal Letters</i>.
    IOP Publishing, 2026. <a href="https://doi.org/10.3847/2041-8213/ae77f3">https://doi.org/10.3847/2041-8213/ae77f3</a>.'
  ieee: 'R. Stein <i>et al.</i>, “TDE 2025abcr: A tidal disruption event in the outskirts
    of a massive galaxy,” <i>The Astrophysical Journal Letters</i>, vol. 1006, no.
    2. IOP Publishing, 2026.'
  ista: '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.'
  mla: 'Stein, Robert, et al. “TDE 2025abcr: A Tidal Disruption Event in the Outskirts
    of a Massive Galaxy.” <i>The Astrophysical Journal Letters</i>, vol. 1006, no.
    2, L57, IOP Publishing, 2026, doi:<a href="https://doi.org/10.3847/2041-8213/ae77f3">10.3847/2041-8213/ae77f3</a>.'
  short: R. Stein, J. Carney, C. Ward, R. Margutti, X.J. Hall, I. Sfaradi, I. Andreoni,
    P. Charalampopoulos, R. Chornock, S. Gezari, G. Mo, Y. Yao, A. Anumarlapudi, E.C.
    Bellm, J.S. Bloom, M. Busmann, I. Caiazzo, S.B. Cenko, M.J. Graham, S.L. Groom,
    D. Gruen, E. Hammerstein, B.C. Kaiser, M.M. Kasliwal, B. O’Connor, A. Palmese,
    J. Purdum, J.C. Rastinejad, R. Riddle, B. Rusholme, J. Sollerman, J.J. Somalwar,
    S. Veilleux, The Astrophysical Journal Letters 1006 (2026).
das_tickbox: '0'
date_created: 2026-08-11T06:19:19Z
date_published: 2026-07-27T00:00:00Z
date_updated: 2026-08-11T07:45:27Z
day: '27'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/2041-8213/ae77f3
external_id:
  arxiv:
  - '2602.10180'
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has_accepted_license: '1'
intvolume: '      1006'
issue: '2'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal Letters
publication_identifier:
  eissn:
  - 2041-8213
  issn:
  - 2041-8205
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: yes
title: 'TDE 2025abcr: A tidal disruption event in the outskirts of a massive galaxy'
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