BVRI Photometry of the Classic Type II-P Supernova 2017eaw in NGC 6946: Day 3 to Day 594

Abstract

Broadband $BVRI$ light curves of SN 2017eaw in NGC 6946 reveal the classic elements of a Type II-P supernova. The observations were begun on 16 May 2017 (UT), approximately 1 day after the discovery was announced, and the photometric monitoring was carried out over a period of nearly 600 days. The light curves show a well-defined plateau and an exponential tail which curves slightly at later times. An approximation to the bolometric light curve is derived and used to estimate the amount of $^{56}$Ni created in the explosion; from various approaches described in the literature, we obtain $M$($^{56}{\rm Ni}$) = 0.115 ($-$0.022,+0.027)$M_{\odot}$. We also estimate that 43\% of the bolometric flux emitted during the plateau phase is actually produced by the $^{56}$Ni chain. Other derived parameters support the idea that the progenitor was a red supergiant.