SN 2011ht: Weak explosion in massive extended envelope

TL;DR

This paper investigates the unusual properties of supernova SN 2011ht, proposing a low-energy explosion interacting with a massive circumstellar envelope to explain its light curve and expansion velocity.

Contribution

It introduces a model of a weak explosion in a massive extended envelope to account for SN 2011ht's observed features, bridging IIn and IIP supernova characteristics.

Findings

Low energy explosion (~6×10^{49} erg) explains the observations.

Ejecta mass is estimated to be ≤ 2 M_{ ext{sun}}.

Circumstellar envelope mass is 6-8 M_{ ext{sun}}.

Abstract

A possibility is explored to account for the light curve and the low expansion velocity of the supernova SN~2011ht, a member of group of three objects showing signatures of both IIn and IIP supernovae. It is argued that the radiated energy and the expansion velocity are consistent with the low energy explosion ($\approx6\times10^{49}$ erg) and $\leq 2 M_{\odot}$ ejecta interacting with the circumstellar envelope of $6-8 M_{\odot}$ and the radius of $~2\times10^{14}$ cm. The test of this scenario is proposed.