The fast evolving type Ib Supernova SN 2015dj in NGC 7371

Abstract

We present the detailed optical evolution of a type Ib SN 2015dj in NGC 7371, using data spanning up to $\sim$ 170 days after discovery. SN 2015dj shares similarity in light curve shape with SN 2007gr and peaks at M${}_V$ = $-17.37\pm$0.02 mag. Analytical modelling of the quasi bolometric light curve yields 0.06$\pm$0.01 M${}_{\odot }$ of ${}^{56}$Ni, ejecta mass $M_{\mathrm{ej}}=1.4_{-0.5}^{+1.3}$ \msol\, and kinetic energy $E_{\mathrm{k}}=0.7_{-0.3}^{+0.6}\times 10^{51}$ erg. The spectral features show a fast evolution and resemble those of spherically symmetric ejecta. The analysis of nebular phase spectral lines indicate a progenitor mass between 13-20 M${}_{\odot }$ suggesting a binary scenario.

16 pages, 11 figures, accepted for publication in ApJ