BVRI photometry of the classic Type II-P supernova 2017eaw in NGC 6946: d 3 to d 594

Abstract

Broadband BV RI 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 Ni) = 0.115 −0.022 +0.027 M ⊙ . 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.

Detection of Late-Time Circumstellar Interaction of SN 2017eaw in NGC 6946

“…R-Band light curve of SN 2017eaw to +899 days since the explosion. This paper's data extends the light curve ofButa & Keel (2019) shown in black. At day +721, the Rband magnitudes begin to level off possibly signalling the beginning of the ejecta-CSM interaction, however no spectra are available at that time.…”

“…SN 2017eaw was discovered on 2017 May 14.238 (UT) (Wiggins 2017;Dong & Stanek 2017) and reached a peak V magnitude of 12.8. Its light curve and spectroscopic evolution followed that of a normal SN II-P (Cheng et al 2017;Xiang et al 2017;Tomasella et al 2017;Tsvetkov et al 2018;Szalai et al 2019;Van Dyk et al 2019;Buta & Keel 2019).…”

“…Observations were reduced using the OS-MOS 1 imaging reduction pipeline in Astropy (Astropy Collaboration et al 2013. Standard methods of aperture photometry were followed in combination with data from Buta & Keel (2019) to calibrate our images and measure magnitudes of SN 2017eaw.…”

“…RESULTS AND DISCUSSION SN 2017eaw's evolution followed that of a standard Type II-P supernova before day ∼ +500 with similar photometric and spectroscopic properties to SN 2004et 2 We adopted an explosion date of 2017 May 12.2 (JD 2,457,885.7) (Van Dyk et al 2019) throughout this paper which is approximately one day earlier than the value used in Rui et al (2019) and Szalai et al (2019). (Tsvetkov et al 2018;Rho et al 2018;Rui et al 2019;Szalai et al 2019;Van Dyk et al 2019;Tinyanont et al 2019;Buta & Keel 2019). There was little evidence of CSM interaction for SN 2017eaw in all previously published results, which cover SN 2017eaw's evolution up to day +594.…”

Progenitor properties of type II supernovae: fitting to hydrodynamical models using Markov chain Monte Carlo methods

“…In this study, we take photometric data and Fe ii λ5169 Å line velocities from Szalai et al (2019). Additional optical photometry can also be found in Tsvetkov et al (2018), Van Dyk et al (2019, Rui et al (2019), andButa &Keel (2019).…”