Recent all-sky surveys have led to the discovery of new types of transients. These include stars disrupted by the central supermassive black hole, and supernovae that are 10–100 times more energetic than typical ones. However, the nature of even more energetic transients that apparently occur in the innermost regions of their host galaxies is hotly debated1,2,3. Here we report the discovery of the most energetic of these to date: PS1-10adi, with a total radiated energy of ~2.3 × 1052 erg. The slow evolution of its light curve and persistently narrow spectral lines over  3 yr are inconsistent with known types of recurring black hole variability. The observed properties imply powering by shock interaction between expanding material and large quantities of surrounding dense matter. Plausible sources of this expanding material are a star that has been tidally disrupted by the central black hole, or a supernova. Both could satisfy the energy budget. For the former, we would be forced to invoke a new and hitherto unseen variant of a tidally disrupted star, while a supernova origin relies principally on environmental effects resulting from its nuclear location. Remarkably, we also discover that PS1-10adi is not an isolated case. We therefore surmise that this new population of transients has previously been overlooked due to incorrect association with underlying central black hole activity.

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We thank G. Ferland, B. Müller, K. Nilsson, M.-Á. Pérez-Torres and K. Poppenhaeger for discussions. E.K. and R.K. acknowledge support from the Science and Technology Facilities Council (STFC; ST/L000709/1). M.F. acknowledges the support of a Royal Society–Science Foundation Ireland University Research Fellowship. This work was partly supported by the European Union FP7 programme through the European Research Council (ERC) grant number 320360. S.J.S acknowledges ERC grant 291222 and STFC grants ST/I001123/1 and ST/L000709/1. J.H. acknowledges financial support from the Finnish Cultural Foundation. C.R.-C. acknowledges support by the Ministry of Economy, Development and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, Chile, and from the Comisión Nacional de Investigación Científica y Tecnológica through the Fondo Nacional de Desarrollo Científico y Tecnológico grant 3150238. The PS1 surveys were 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 Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching, 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., the National Central University of Taiwan, the Space Telescope Science Institute, NASA (National Aeronautics and Space Administration) under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University and the Los Alamos National Laboratory. The Catalina Sky Survey is funded by NASA under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. The Catalina Real-Time Transient Survey is supported by the US National Science Foundation under grants AST-0909182 and AST-1313422. This work is based on observations made with the NOT, the LT, the WHT, the WISE, Swift and the Karl G. Jansky Very Large Array.

Author information


  1. Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, UK

    • E. Kankare
    • , R. Kotak
    • , S. J. Smartt
    • , C. Inserra
    •  & K. W. Smith
  2. Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Piikkiö, Finland

    • S. Mattila
    • , J. Harmanen
    • , T. Kangas
    •  & T. Reynolds
  3. Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Piikkiö, Finland

    • S. Mattila
  4. Oskar Klein Centre, Department of Astronomy, AlbaNova, Stockholm University, Stockholm, Sweden

    • P. Lundqvist
  5. Department of Physics, Durham University, Durham, UK

    • M. J. Ward
  6. Institute of Astronomy, University of Cambridge, Cambridge, UK

    • M. Fraser
  7. School of Physics, O’Brien Centre for Science North, University College Dublin, Dublin, Ireland

    • M. Fraser
  8. Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK

    • A. Lawrence
    •  & A. Bruce
  9. Imperial College of Science Technology and Medicine, London, UK

    • W. P. S. Meikle
  10. Department of Physics and Astronomy, University College London, London, UK

    • S. J. Hutton
  11. Department of Physics and Astronomy, University of Southampton, Southampton, UK

    • C. Inserra
  12. INAF—Osservatorio Astronomico di Padova, Padua, Italy

    • A. Pastorello
  13. Nordic Optical Telescope, Santa Cruz de la Palma, Spain

    • T. Reynolds
  14. Millennium Institute of Astrophysics, Santiago, Chile

    • C. Romero-Cañizales
  15. Núcleo de Astronomía de la Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Santiago, Chile

    • C. Romero-Cañizales
  16. Department of Physics, University of California, Davis, CA, USA

    • S. Valenti
  17. Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI, USA

    • K. C. Chambers
    • , K. W. Hodapp
    • , M. E. Huber
    • , N. Kaiser
    • , R.-P. Kudritzki
    • , E. A. Magnier
    • , J. L. Tonry
    • , R. J. Wainscoat
    •  & C. Waters


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E.K. performed the data analysis and wrote the manuscript. R.K., S.M., P.L., M.J.W., M.F., A.L., S.J.S., W.P.S.M., S.J.H., C.I. and A.P. contributed to the physical interpretation. A.B. carried out follow-up observations with the WHT. C.R.-C. carried out the radio data reductions. J.H., T.K. and T.R. carried out follow-up observations with the NOT. S.V., K.W.S. and S.J.S. built the Pan-STARRS Transient Science Server hosted at Queen’s University Belfast. K.C.C., K.W.H., M.E.H., N.K., R.-P.K., E.A.M., J.L.T., R.J.W. and C.W. are PS1 builders.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to E. Kankare.

Electronic supplementary material

  1. Supplementary Information

    Supplementary Tables 1–4, Supplementary Figures 1–4 and Supplementary References