SN 2011ht: Weak explosion in massive extended envelope

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.