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

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 circum-stellar material. 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.

Accepted for publication in MNRAS. 15 pages, 11 figures, 5 tables

References in corpus (16)

• Pulsational pair instability as an explanation for the most luminous supernovae
• A giant outburst two years before the core-collapse of a massive star
• SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-Rich Circumstellar Medium
• A New Class of Luminous Transients and A First Census of Their Massive Stellar Progenitors
• Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events
• Luminous Blue Variables as the progenitors of supernovae with quasi-periodic radio modulations
• The 2008 Luminous Optical Transient in the Nearby Galaxy NGC 300
• An Intermediate Luminosity Transient in NGC300: The Eruption of a Dust-Enshrouded Massive Star
• SN 1994W: An Interacting Supernova or Two Interacting Shells?
• SN 2008S: A Cool Super-Eddington Wind in a Supernova Impostor
• Massive stars exploding in a He-rich circumstellar medium III. SN 2006jc: IR echoes from new and old dust in the progenitor CSM
• A Blast Wave from the 1843 Eruption of Eta Carinae
• Faint Supernovae and Supernova Impostors: Case studies of SN2002kg/NGC2403-V37 and SN 2003gm
• Early Formation of Dust in the Ejecta of Type Ib SN 2006jc and Temperature and Mass of the Dust
• Environments of interacting transients: Impostors and type IIn supernovae
• The Peculiar Type Ib Supernova 2006jc: A WCO Wolf-Rayet Star Explosion

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