The interaction of a supernova with a circumstellar medium (CSM) can dramatically increase the emitted luminosity by converting kinetic energy to thermal energy. In ‘superluminous’ supernovae of type IIn—named for narrow hydrogen lines 1 in their spectra—the integrated emission can reach 2–6 ~10 51 erg, attainable by thermalizing most of the kinetic energy of a conventional supernova. A few transients in the centres of active galaxies have shown similar spectra and even larger energies 7,8, but are difficult to distinguish from accretion onto the supermassive black hole. Here we present a new event, SN2016aps, offset from the centre of a low-mass galaxy, that radiated ≳5 × 10 51 erg, necessitating a hyper-energetic supernova explosion. We find a total (supernova ejecta + CSM) mass likely exceeding 50−100 M ⊙, with energy ≳10 52 erg, consistent with some models of pair-instability supernovae or pulsational pair-instability supernovae—theoretically predicted thermonuclear explosions from helium cores >50 M ⊙. Independent of the explosion mechanism, this event demonstrates the existence of extremely energetic stellar explosions, detectable at very high redshifts, and provides insight into dense CSM formation in the most massive stars.
Bibliographical noteFunding Information:
M.N. is a Royal Astronomical Society Research Fellow. The Berger Time-Domain Group acknowledge NSF grant AST-1714498 and NASA grant NNX15AE50G. R.L. acknowledges a Marie Skłodowska-Curie Individual Fellowship within the Horizon 2020 European Union Framework (H2020-MSCA-IF-2017-794467). W.-f.F. and K.P. acknowledge support from NSF grant numbers AST-1814782 and AST-1909358. The Margutti group acknowledges NSF grant number AST 1909796, NASA grants 80NSSC19K0384 and 80NSSC19K0646. A.A.M. is supported by the LSST Corporation, the Brinson Foundation, the Moore Foundation via the LSSTC Data Science Fellowship Program, and the CIERA Fellowship Program. A.V.-G. acknowledges support by the Danish National Research Foundation (DNRF132). Data were obtained via the NASA/ESA Hubble Space Telescope archive at the Space Telescope Science Institute, the Swift archive, the Smithsonian Astrophysical Observatory OIR Data Center, the MMT Observatory, the MDM Observatory, the Gemini Observatory, operated by the Association of Universities for Research in Astronomy, Inc., under agreement with the NSF, and the W.M. Keck Observatory, operated as a partnership among the California Institute of Technology, the University of California, and NASA. Operation of the Pan-STARRS1 telescope is supported by NASA under Grants NNX12AR65G and NNX14AM74G. The authors respect the very significant cultural role of Mauna Kea within the indigenous Hawaiian community.
© 2020, The Author(s), under exclusive licence to Springer Nature Limited.
- Astrophysics - High Energy Astrophysical Phenomena
- Astrophysics - Solar and Stellar Astrophysics