SN 2013df, a double-peaked IIb supernova from a compact progenitor and an extended H envelope

TL;DR

SN 2013df is a double-peaked Type IIb supernova from a compact progenitor with an extended hydrogen envelope, exhibiting asymmetric explosion features and providing estimates of ejecta mass, explosion energy, and progenitor characteristics.

Contribution

This study provides detailed optical and UV observations of SN 2013df, modeling its light curve to estimate key explosion parameters and progenitor properties, highlighting its similarity to SN 1993J.

Findings

Double-peaked light curve similar to SN 1993J and 2011fu.

Ejecta mass estimated between 0.8-1.4 M$_{ ext{odot}}$.

Explosion energy estimated between 0.4-1.2 x 10^{51} erg.

Abstract

Optical observations of the type IIb SN 2013df from a few days to about 250 days after explosion are presented. These observations are complemented with UV photometry taken by \textit{SWIFT} up to 60 days post-explosion. The double-peak optical light curve is similar to those of SNe 1993J and 2011fu although with different decline and rise rates. From the modelling of the bolometric light curve, we have estimated that the total mass of synthesised $^{56}$Ni in the explosion is $\sim0.1$ M$_{\odot}$, while the ejecta mass is $0.8-1.4$ M$_{\odot}$ and the explosion energy $0.4-1.2 \times 10^{51}$erg. In addition, we have estimated a lower limit to the progenitor radius ranging from $64-169$ $R_{\odot}$. The spectral evolution indicates that SN 2013df had a hydrogen envelope similar to SN 1993J ($\sim 0.2$ M$_{\odot}$). The line profiles in nebular spectra suggest that the explosion was asymmetric with the presence of clumps in the ejecta, while the [O\,{\sc i}] $\lambda$$\lambda$$6300$, $6364$ luminosities, may indicate that the progenitor of SN 2013df was a relatively low mass star ( $\sim 12-13 $ M$_{\odot}$).