article published yes Robert Stein author Jonathan Carney author Charlotte Ward author Raffaella Margutti author Xander J. Hall author Itai Sfaradi author Igor Andreoni author Panos Charalampopoulos author Ryan Chornock author Suvi Gezari author Geoffrey Mo author Yuhan Yao author Akash Anumarlapudi author Eric C. Bellm author Joshua S. Bloom author Malte Busmann author Ilaria Caiazzo author 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d0000-0002-4770-5388 S. Bradley Cenko author Matthew J. Graham author Steven L. Groom author Daniel Gruen author Erica Hammerstein author Benjamin C. Kaiser author Mansi M. Kasliwal author Brendan O’Connor author Antonella Palmese author Josiah Purdum author Jillian C. Rastinejad author Reed Riddle author Ben Rusholme author Jesper Sollerman author Jean J. Somalwar author Sylvain Veilleux author IlCa department 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. https://research-explorer.ista.ac.at/download/22675/22682/2026_AstrophysicalJourLetters_Stein.pdf application/pdfno IOP Publishing2026 eng 2041-8205 2041-8213 2602.1018010.3847/2041-8213/ae77f3 10062 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> 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> 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). 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, 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>. 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>. 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. 226752026-08-11T06:19:19Z2026-08-11T07:45:27Z