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Published November 4, 2025 | Version Supplemental material
Journal Article Open

An extremely luminous flare recorded from a supermassive black hole

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Borough of Manhattan Community College
  • 3. ROR icon American Museum of Natural History
  • 4. ROR icon City University of New York
  • 5. ROR icon Flatiron Institute
  • 6. ROR icon Jet Propulsion Lab
  • 7. ROR icon Princeton University
  • 8. ROR icon Eureka Scientific
  • 9. ROR icon University of California, Berkeley
  • 10. ROR icon University of Southampton
  • 11. ROR icon Ruhr University Bochum
  • 12. ROR icon University of Washington
  • 13. ROR icon Infrared Processing and Analysis Center

Abstract

Since their discovery more than 60 years ago, accreting supermassive black holes in active galactic nuclei (AGN) have been recognized as highly variable sources, requiring an extremely compact, dynamic environment. Their variability is related to several phenomena, including changing accretion rates, temperature changes, foreground absorbers and structural changes to the accretion disk. Spurred by a new generation of time-domain surveys, the extremes of black hole variability are now being probed. Here we describe the discovery of an extreme flare by the AGN J224554.84+374326.5, which brightened by more than a factor of 40 in 2018. The source has slowly faded since then. The total emitted ultraviolet and optical energy to date is ~1054 erg, which represents the complete conversion of approximately one solar mass into electromagnetic radiation. This flare is 30 times more powerful than the previous most powerful AGN transient. Very few physical events in the Universe can liberate this much electromagnetic energy. We discuss potential mechanisms, including the tidal disruption of a high-mass star (>30 M⊙), gravitational lensing of an AGN flare or supernova, or a supermassive (pair-instability) supernova in the accretion disk of an AGN. We favour the tidal disruption of a massive star in a prograde orbit in an AGN disk.

Copyright and License

© The Author(s), under exclusive licence to Springer Nature Limited 2025.

Acknowledgement

M.J.G. acknowledges support from the US National Science Foundation (NSF) (Grant No. AST-2108402). B.M. and K.E.S.F. are supported by the NSF (Grant Nos. AST-1831415 and AST-2206096) and the Simons Foundation (Grant No. 533845). The work by D.S. was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA (Grant No. 80NM0018D0004). S.G.D. acknowledges generous support from the Ajax Foundatio. P.M.V. acknowledges support from the DFG through the Collaborative Research Center SFB1491 Cosmic Interacting Matters – From Source to Signal. P.W. acknowledges support from the Science and Technology Facilities Council (Grant No. ST/Z510269/1). This work is based on observations obtained with the 48-inch Samuel Oschin Telescope and the 60-inch telescope at the Palomar Observatory as part of the ZTF project. ZTF is supported by the NSF (Grant Nos. AST-1440341 and AST-2034437) and a collaboration including current partners Caltech, IPAC, the Oskar Klein Center at Stockholm University, the University of Maryland, University of California, Berkeley, the University of Wisconsin at Milwaukee, University of Warwick, Ruhr University Bochum, Cornell University, Northwestern University and Drexel University. Operations are conducted by COO, IPAC and UW. This publication makes use of data products from WISE, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, and NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology. WISE and NEOWISE are funded by NASA.

Data Availability

All photometry and spectroscopy used for J2245+3743 is available via a public GitHub repository at www.github.com/doccosmos/superman. All spectra and photometry for other sources in figures were from public archives.

Code Availability

KCWISkyWizard is an open source tool available via GitHub at http://github.com/zhuyunz/KSkyWizard.

Supplemental Material

Supplementary Discussion, Figs. 1–9 and Table 1.

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Additional details

Related works

Describes
Journal Article: https://rdcu.be/eOBRA (ReadCube)
Is new version of
Discussion Paper: arXiv:2511.02178 (arXiv)
Is supplemented by
Dataset: http://www.github.com/doccosmos/superman (URL)
Software: http://github.com/zhuyunz/KSkyWizard (URL)
Supplemental Material: https://static-content.springer.com/esm/art%3A10.1038%2Fs41550-025-02699-0/MediaObjects/41550_2025_2699_MOESM1_ESM.pdf (URL)

Funding

National Science Foundation
AST-2108402
National Science Foundation
AST-1831415
National Science Foundation
AST-2206096
Simons Foundation
533845
National Aeronautics and Space Administration
80NM0018D0004
Deutsche Forschungsgemeinschaft
SFB1491
Science and Technology Facilities Council
ST/Z510269/1
National Science Foundation
AST-1440341
National Science Foundation
AST-2034437
Jet Propulsion Laboratory

Dates

Accepted
2025-10-03
Available
2025-11-04
Published online

Caltech Custom Metadata

Caltech groups
Astronomy Department, Center for Data-Driven Discovery (CDDD), Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility, Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
In Press