Interacting supernovae and supernova impostors. SN 2007sv: the major eruption of a massive star in UGC 5979

L. Tartaglia*, A. Pastorello, S. Taubenberger, E. Cappellaro, J. R. Maund, S. Benetti, T. Boles, F. Bufano, G. Duszanowicz, N. Elias-Rosa, A. Harutyunyan, L. Hermansson, P. Hoflich, K. Maguire, H. Navasardyan, S. J. Smartt, F. Taddia

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

We report the results of the photometric and spectroscopic monitoring campaign of the transient SN 2007sv. The observables are similar to those of Type IIn supernovae, a well-known class of objects whose ejecta interact with pre-existing circumstellar material (CSM). The spectra show a blue continuum at early phases and prominent Balmer lines in emission; however, the absolute magnitude at the discovery of SN 2007sv (M-R=-14.25 +/- 0.38) indicate it to be most likely a supernova impostor. This classification is also supported by the lack of evidence in the spectra of very high velocity material as expected in supernova ejecta. In addition, we find no unequivocal evidence of broad lines of alpha- and/or Fe-peak elements. The comparison with the absolute light curves of other interacting objects (including Type IIn supernovae) highlights the overall similarity with the prototypical impostor SN 1997bs. This supports our claim that SN 2007sv was not a genuine supernova, and was instead a supernova impostor, most likely similar to the major eruption of a luminous blue variable.

Original languageEnglish
Pages (from-to)117-131
Number of pages15
JournalMonthly Notices of the Royal Astronomical Society
Volume447
Issue number1
Early online date12 Dec 2014
DOIs
Publication statusPublished - 11 Feb 2015

Keywords

  • supernovae: individual: SN 2007sv
  • galaxies: individual: UGC 5979
  • RICH CIRCUMSTELLAR MEDIUM
  • LUMINOUS BLUE VARIABLES
  • IIN SUPERNOVAE
  • CORE-COLLAPSE
  • SPECTRAL EVOLUTION
  • NEARBY GALAXIES
  • LIGHT CURVES
  • ETA-CARINAE
  • NGC 300
  • PROGENITORS

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