SN 2019edo: A Type II-P Supernova with a Fast Brightness Rise and a Short Plateau Phase

Abstract

We present the results of BVRI photometry for the type II-P supernova (SN) 2019edo in NGC 4162 obtained from April 29, 2019, to January 26, 2020, with several telescopes, including the 60-cm telescope at the Caucasus Mountain Observatory of the Sternberg Astronomical Institute of the Moscow State University. The shape of the light curves is typical for SN II-P. However, the plateau lasted for about 76 days, which is less than the typical value for SN of this class, while the luminosity rise to the peak was unusually fast. The absolute $V$ magnitude at maximum light was $-16\overset{m}{.}$9, which is close to the mean value for SN II-P. The brightness decline rate at the late phase is slightly higher than the expected one for the radiation due to ${}^{56}$Co decay. As a result of our radiation-hydrodynamics simulations of the SN explosion with the STELLA code, we have managed to consistently reproduce the initial rise and plateau phases in the light curves. The constructed SN model has the following parameters: an ejecta mass $M_{\textrm{env}}=6.6M_{\odot}$, an SN progenitor radius $R_{0}=500R_{\odot}$, and a mass of radioactive ${}^{56}\textrm{Ni}\approx 0.05M_{\odot}$. The SN progenitor was inside a cocoon, a stellar wind, with a total mass $M_{\textrm{wind}}\approx 0.01M_{\odot}$ and a radius $R_{\textrm{wind}}=10^{15}$ cm. The energy release during the explosion was $E_{\textrm{burst}}=0.8\times 10^{51}$ erg.