The Type Ibn Supernova 2019kbj -- Indications for Diversity in Type Ibn Supernova Progenitors

Abstract

Type Ibn supernovae (SNe) are a rare class of stellar explosions whose progenitor systems are not yet well determined. We present and analyze observations of the Type Ibn SN 2019kbj, and model its light curve in order to constrain its progenitor and explosion parameters. SN 2019kbj shows roughly constant temperature during the first month after peak, indicating a power source (likely circumstellar material interaction) that keeps the continuum emission hot at ~15,000K. Indeed, we find that the radioactive decay of Ni56 is disfavored as the sole power source of the bolometric light curve. A radioactive decay + circumstellar-material (CSM) interaction model, on the other hand, does reproduce the bolometric emission well. The fits prefer a uniform-density CSM shell rather than CSM due to a steady mass-loss wind, similar to what is seen in other Type Ibn SNe. The uniform-density CSM shell model requires ~0.1 solar masses of Ni56 and ~1 solar mass of total ejecta to reproduce the light curve. SN 2019kbj differs in this manner from another Type Ibn SN with derived physical parameters, SN 2019uo, for which an order of magnitude lower Ni56 mass and larger ejecta mass were derived. This points towards a possible diversity in SN Ibn progenitor systems and explosions.

Accepted to ApJ

References in corpus (13)

• Physical Properties of Wolf-Rayet Stars
• A giant outburst two years before the core-collapse of a massive star
• SOUSA: the Swift Optical/Ultraviolet Supernova Archive
• The Broad-lined Type Ic SN 2003jd
• Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events
• 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
• Circumstellar Interaction Powers the Light Curves of Luminous Rapidly Evolving Optical Transients
• 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
• Flash ionization signatures in the type Ibn supernova SN 2019uo
• Errors When Constraining Hot Blackbody Parameters with Optical Photometry
• ASASSN-14ms:the Most Energetic Known Explosion of a Type Ibn Supernova and its Physical Origin

Cited by in corpus (5)

• Mass-transferring binary stars as progenitors of interacting hydrogen-free supernovae
• A characterization of ASAS-SN core-collapse supernova environments with VLT+MUSE: I. Sample selection, analysis of local environments, and correlations with light curve properties
• Massive stars exploding in a He-rich circumstellar medium. XI. Diverse evolution of five Ibn SNe 2020nxt, 2020taz, 2021bbv, 2023utc and 2024aej
• Massive stars exploding in a He-rich circumstellar medium $-$ X. Flash spectral features in the Type Ibn SN 2019cj and observations of SN 2018jmt
• SN 2024abvb: A Type Icn Supernova in the Outskirts of its Host Galaxy