Evolution of A Peculiar Type Ibn Supernova SN 2019wep

Abstract

We present a high-cadence short term photometric and spectroscopic monitoring campaign of a type Ibn SN 2019wep, which is one of the rare SN Ibn after SNe 2010al and 2019uo to display signatures of flash ionization (\ion{He}{2}, \ion{C}{3}, \ion{N}{3}). We compare the decline rates and rise time of SN 2019wep with other SNe Ibn and fast transients. The post-peak decline in all bands (0.1 mag d${}^{-1}$) are consistent with SNe Ibn but less than the fast transients. On the other hand, the $\Delta$m${}_{15}$ values are slightly lower than the average values for SNe Ibn but consistent with the fast transients. The rise time is typically shorter than SNe Ibn but longer than fast transients. SN 2019wep lies at the fainter end of SNe Ibn but possesses an average luminosity amongst the fast transients sample. The peculiar color evolution places it between SNe Ib and the most extreme SNe Ibn. The bolometric light curve modelling shows resemblance with SN 2019uo with ejecta masses consistent with SNe Ib. SN 2019wep belongs to the "P cygni" sub-class of SNe Ibn and shows faster evolution in line velocities as compared to the "emission" sub-class. The post-maximum spectra show close resemblance with ASASSN-15ed hinting it to be of SN Ib nature. The low \ion{He}{1} CSM velocities and residual H$\alpha$ further justifies it and gives evidence of an intermittent progenitor between WR and LBV star.

19 pages, 14 figures, 2 Tables, Accepted for publication in ApJ main journal

References in corpus (24)

• A giant outburst two years before the core-collapse of a massive star
• The Zwicky Transient Facility: Surveys and Scheduler
• A Wolf-Rayet-like progenitor of supernova SN 2013cu from spectral observations of a wind
• Rapidly-Evolving and Luminous Transients from Pan-STARRS1
• SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-Rich Circumstellar Medium
• Unifying Type II Supernova Light Curves with Dense Circumstellar Material
• Optical Spectra of 73 Stripped-Envelope Core-Collapse Supernovae
• Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events
• Luminous Blue Variables are Antisocial: Their Isolation Implies that they are Kicked Mass Gainers in Binary Evolution
• Investigating the properties of stripped-envelope supernovae, what are the implications for their progenitors?
• Early-time spectra of supernovae and their precursor winds: the luminous blue variable/yellow hypergiant progenitor of SN 2013cu
• Massive stars exploding in a He-rich circumstellar medium. II. The transitional case of SN 2005la
• Massive stars exploding in a He-rich circumstellar medium. IV. Transitional Type Ibn Supernovae
• Properties of Type Ibn Supernovae: Implications for the Progenitor Evolution and the Origin of a Population of Rapid Transients
• The Peculiar Type Ib Supernova 2006jc: A WCO Wolf-Rayet Star Explosion
• Type Ibn Supernovae May not all Come from Massive Stars
• Massive stars exploding in a He-rich circumstellar medium. V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
• Massive stars exploding in a He-rich circumstellar medium. VI. Observations of two distant Type Ibn supernova candidates discovered by La Silla-QUEST
• The Peculiar Transient AT2018cow: A Possible Origin of A Type Ibn/IIn Supernova
• Flash ionization signatures in the type Ibn supernova SN 2019uo
• LSQ13ddu: A rapidly-evolving stripped-envelope supernova with early circumstellar interaction signatures
• Bolometric Lightcurves of Peculiar Type II-P Supernovae
• Optical studies of two stripped envelope supernovae SN 2015ap (Type Ib) and SN 2016P (Type Ic)
• ASASSN-14ms:the Most Energetic Known Explosion of a Type Ibn Supernova and its Physical Origin

Cited by in corpus (1)

• Extreme mass loss in low-mass type Ib/c supernova progenitors