Type Ibn supernova SN~2010al: Powerful mass loss half year prior to the explosion

TL;DR

This paper analyzes the properties of the Type Ibn supernova SN 2010al, revealing that it resulted from a Wolf-Rayet star explosion with significant mass loss occurring within half a year before the event, involving a dense circumstellar shell.

Contribution

It introduces a combined spectral and interaction model to infer supernova and circumstellar shell parameters, highlighting recent mass loss prior to explosion.

Findings

Supernova explosion energy of (1-1.5)×10^{51} erg.

Dense circumstellar shell mass of about 0.1 solar masses.

Mass loss occurred within 0.4 years before core collapse.

Abstract

Type Ibn supernova SN~2010al is explored to infer parameters of supernova and a circumstellar (CS) shell. The CS interaction model combined with the spectral model of 4600\AA\ blend suggests the explosion of a WR star with the energy of $(1-1.5)\times10^{51}$ erg inside a dense confined CS shell with the mass of $\sim0.1$\msun\ and kinetic energy of $\sim 10^{48}$ erg. The confined CS shell has been formed during the last 0.4 yr prior to the core collapse.