The flare of radiation from the tidal disruption and accretion of a star can be used as a marker for supermassive black holes that otherwise lie dormant and undetected in the centres of distant galaxies1. Previous candidate flares2,3,4,5,6 have had declining light curves in good agreement with expectations, but with poor constraints on the time of disruption and the type of star disrupted, because the rising emission was not observed. Recently, two ‘relativistic’ candidate tidal disruption events were discovered, each of whose extreme X-ray luminosity and synchrotron radio emission were interpreted as the onset of emission from a relativistic jet7,8,9,10. Here we report a luminous ultraviolet–optical flare from the nuclear region of an inactive galaxy at a redshift of 0.1696. The observed continuum is cooler than expected for a simple accreting debris disk, but the well-sampled rise and decay of the light curve follow the predicted mass accretion rate and can be modelled to determine the time of disruption to an accuracy of two days. The black hole has a mass of about two million solar masses, modulo a factor dependent on the mass and radius of the star disrupted. On the basis of the spectroscopic signature of ionized helium from the unbound debris, we determine that the disrupted star was a helium-rich stellar core.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    Tidal disruption of stars by black holes of 10 to the 6th-10 to the 8th solar masses in nearby galaxies. Nature 333, 523–528 (1988)

  2. 2.

    & The giant X-ray outbursts in NGC 5905 and IC 3599: follow-up observations and outburst scenarios. Astron. Astrophys. 343, 775–787 (1999)

  3. 3.

    et al. A huge drop in the X-ray luminosity of the nonactive galaxy RX J1242.6–1119A, and the first postflare spectrum: testing the tidal disruption scenario. Astrophys. J. 603, L17–L20 (2004)

  4. 4.

    et al. Evolution of tidal disruption candidates discovered by XMM-Newton. Astron. Astrophys. 489, 543–554 (2008)

  5. 5.

    et al. Luminous thermal flares from quiescent supermassive black holes. Astrophys. J. 698, 1367–1379 (2009)

  6. 6.

    et al. Optical discovery of probable stellar tidal disruption flares. Astrophys. J. 741, 73–96 (2011)

  7. 7.

    et al. A possible relativistic jetted outburst from a massive black hole fed by a tidally disrupted star. Science 333, 203–206 (2011)

  8. 8.

    et al. Relativistic jet activity from the tidal disruption of a star by a massive black hole. Nature 476, 421–424 (2011)

  9. 9.

    et al. Birth of a relativistic outflow in the unusual γ-ray transient Swift J164449.3+573451. Nature 476, 425–428 (2011)

  10. 10.

    et al. Swift J2058.4+0516: discovery of a possible second relativistic tidal disruption flare. Preprint at 〈〉 (2011)

  11. 11.

    in The Center of the Galaxy (ed. ) 543–553 (IAU Symp. 136, Kluwer, 1989)

  12. 12.

    & The tidal disruption of a star by a massive black hole. Astrophys. J. 346, L13–L16 (1989)

  13. 13.

    Flares from the tidal disruption of stars by massive black holes. Astrophys. J. 514, 180–187 (1999)

  14. 14.

    et al. The Pan-STARRS wide-field optical/NIR imaging survey. Proc. SPIE 7733, 77330E (2010)

  15. 15.

    et al. The Galaxy Evolution Explorer: a space ultraviolet survey mission. Astrophys. J. 619, L1–L6 (2005)

  16. 16.

    et al. The eighth data release of the Sloan Digital Sky Survey: first data from SDSS-III. Astrophys. J. Suppl. Ser. 193, 29–45 (2011)

  17. 17.

    et al. The UKIRT Infrared Deep Sky Survey (UKIDSS). Mon. Not. R. Astron. Soc. 379, 1599–1617 (2007)

  18. 18.

    & K-corrections and filter transformations in the ultraviolet, optical, and near-infrared. Astron. J. 133, 734–754 (2007)

  19. 19.

    & On the black hole mass-bulge mass relation. Astrophys. J. 604, L89–L92 (2004)

  20. 20.

    , & Stellar disruption by a supermassive black hole: is the light curve really proportional to t−5/3? Mon. Not. R. Astron. Soc. 392, 332–340 (2009)

  21. 21.

    & Optical flares from the tidal disruption of stars by massive black holes. Mon. Not. R. Astron. Soc. 400, 2070–2084 (2009)

  22. 22.

    The UV peak in active galactic nuclei: a false continuum from blurred reflection? Preprint 〈〉 (2011)

  23. 23.

    & Optical appearance of the debris of a star disrupted by a massive black hole. Astrophys. J. 489, 573–578 (1997)

  24. 24.

    & The stars of the galactic center. Astrophys. J. 624, L25–L27 (2005)

  25. 25.

    , , & Gravitational waves and X-ray signals from stellar disruption by a massive black hole. Astrophys. J. 615, 855–865 (2004)

  26. 26.

    et al. Discovery of a stripped red giant core in a bright eclipsing binary system. Mon. Not. R. Astron. Soc. 418, 1156–1164 (2011)

  27. 27.

    , & Tidal disruption of a solar-type star by a supermassive black hole. Astrophys. J. 545, 772–780 (2000)

  28. 28.

    et al. The X-ray-to-optical properties of optically selected active galaxies over wide luminosity and redshift ranges. Astron. J. 131, 2826–2842 (2006)

  29. 29.

    et al. The Liverpool Telescope: performance and first results. Proc. SPIE 5389, 679 (2004)

Download references


We thank H. Tananbaum for approving our Chandra Director’s Discretionary Time request. We are grateful to G. Lodato for providing the tidal disruption event models in tabular form, and to S. Moran for running software to calculate the host-galaxy K-corrections. We thank R. E. Williams for discussions on the line emission in the spectra. S.G. was supported by NASA through a Hubble Fellowship grant awarded by the Space Telescope Science Institute, which is operated by AURA Inc. for NASA. Partial support for this work was provided by the National Science Foundation. The PS1 survey has been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Inc. and the National Central University of Taiwan, and by NASA under a grant issued through the Planetary Science Division of the NASA Science Mission Directorate. We acknowledge NASA’s support for construction, operation, and science analysis of the GALEX mission, which was developed in cooperation with Centre National d’Etudes Spatiales of France and the Korean Ministry of Science and Technology. Some of the observations reported here were obtained at the MMT Observatory, which is a joint facility of the Smithsonian Institution and the University of Arizona, and at the Liverpool Telescope, which is operated with financial support from the UK Science and Technology Facilities Council. The computations in this paper were run on the Odyssey cluster supported by the FAS Science Division Research Computing Group at Harvard University. R.J.F. is a Clay Fellow.

Author information


  1. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA

    • S. Gezari
    • , T. Heckman
    • , C. Norman
    • , D. Scolnic
    •  & A. G. Riess
  2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA

    • R. Chornock
    • , E. Berger
    • , P. J. Challis
    • , G. Narayan
    • , R. J. Foley
    • , G. H. Marion
    • , L. Chomiuk
    • , A. Soderberg
    • , R. P. Kirshner
    •  & C. W. Stubbs
  3. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218, USA

    • A. Rest
  4. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, Hawaii 96822, USA

    • M. E. Huber
    • , J. L. Tonry
    • , W. S. Burgett
    • , K. C. Chambers
    • , J. N. Heasley
    • , N. Kaiser
    • , R.-P. Kudritzki
    • , E. A. Magnier
    •  & J. S. Morgan
  5. California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA

    • K. Forster
    • , J. D. Neill
    •  & D. C. Martin
  6. Institute for Astronomy, University of Edinburgh Scottish Universities Physics Alliance, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK

    • A. Lawrence
  7. Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, UK

    • K. Smith
    •  & S. J. Smartt
  8. Pittsburgh Particle Physics, Astrophysics, and Cosmology Center, Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, Pennsylvania 15260, USA

    • W. M. Wood-Vasey
  9. Planetary Science Institute, 1700 East Fort Lowell, Tucson, Arizona 85719, USA

    • T. Grav
  10. Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA

    • P. A. Price


  1. Search for S. Gezari in:

  2. Search for R. Chornock in:

  3. Search for A. Rest in:

  4. Search for M. E. Huber in:

  5. Search for K. Forster in:

  6. Search for E. Berger in:

  7. Search for P. J. Challis in:

  8. Search for J. D. Neill in:

  9. Search for D. C. Martin in:

  10. Search for T. Heckman in:

  11. Search for A. Lawrence in:

  12. Search for C. Norman in:

  13. Search for G. Narayan in:

  14. Search for R. J. Foley in:

  15. Search for G. H. Marion in:

  16. Search for D. Scolnic in:

  17. Search for L. Chomiuk in:

  18. Search for A. Soderberg in:

  19. Search for K. Smith in:

  20. Search for R. P. Kirshner in:

  21. Search for A. G. Riess in:

  22. Search for S. J. Smartt in:

  23. Search for C. W. Stubbs in:

  24. Search for J. L. Tonry in:

  25. Search for W. M. Wood-Vasey in:

  26. Search for W. S. Burgett in:

  27. Search for K. C. Chambers in:

  28. Search for T. Grav in:

  29. Search for J. N. Heasley in:

  30. Search for N. Kaiser in:

  31. Search for R.-P. Kudritzki in:

  32. Search for E. A. Magnier in:

  33. Search for J. S. Morgan in:

  34. Search for P. A. Price in:


S.G. designed the observations and the transient detection pipeline for the GALEX TDS, and measured the ultraviolet photometry of PS1-10jh. K.F. and J.D.N coordinated, and D.C.M. facilitated, the GALEX TDS observations. A.R. designed the PhotPipe transient detection pipeline hosted by Harvard/CfA for the PS1 Medium Deep Survey (MDS), and measured the optical photometry of PS1-10jh. R.C. designed, implemented and analysed the MMT optical spectroscopy observations, and contributed to the operation of PhotPipe and the visual inspection of transient alerts. E.B. proposed and facilitated the MMT observations. M.E.H., G.N., D.S. and R.J.F. contributed to the operation of PhotPipe and the visual inspection of transient alerts. P.J.C., R.J.F., G.H.M., L.C. and A.S. contributed to the MMT observations. S.J.S. designed, and K.S. operated, the transient pipeline for PS1 MDS hosted by Queen’s University Belfast. C.W.S., J.L.T. and W.M.W.-V. facilitated the transient pipelines for PS1 MDS. W.S.B., K.C.C., T.G., J.N.H., N.K., R.-P.K., E.A.M., J.S.M., P.A.P., C.W.S. and J.L.T. helped build the PS1 system. S.G. requested the Director’s Discretionary Time Chandra X-ray observation and analysed the data. A.L. obtained the Liverpool Telescope optical imaging observations and analysed the data, and stimulated discussions on the nature of the SED of PS1-10jh. S.G. analysed and modelled the multicolour light curve and the SED of PS1-10jh. T.H. and C.N. stimulated discussions on the nature of the disrupted star. The paper was organized and written by S.G., and all authors provided feedback on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to S. Gezari.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Text and Data 1-7, Supplementary Figures 1-5, Supplementary Tables 1-3 and additional references.

About this article

Publication history







By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.