Paper

The Type II-P Supernova 2019mhm and Constraints on Its Progenitor System

Kilpatrick, C D, Rojas-Bravo, C, Vazquez, J, Foley, R J, Piro, A L, Rest, A, Dimitriadis, G

2023

Overview

We present pre- and post-explosion observations of the Type II-P supernova (SN~II-P) 2019mhm located in NGC~6753. Based on optical spectroscopy and photometry, we show that SN\\,2019mhm exhibits broad lines of hydrogen with a velocity of \\(-8500\\pm200\\)~km~s\\(^{-1}\\) and a \\(111\\pm2\\)~day extended plateau in its luminosity, typical of the Type II-P subclass. We also fit its late-time bolometric light curve and infer that it initially produced a \\({}^{56}\\)Ni mass of \\(1.3 \\times 10^{-2}\\)~M\\(_{\\odot} \\pm 5.5 \\times 10^{-4}\\)~\\(M_\\odot\\). Using imaging from the Wide Field Planetary Camera 2 on the {\\it Hubble Space Telescope} obtained 19~years before explosion, we aligned to a post-explosion Wide Field Camera 3 image and demonstrate that there is no detected counterpart to the SN to a limit of \\(>\\)24.53~mag in F814W, corresponding to an absolute magnitude limit of \\(M_{\\rm F814W} < -7.7\\)~mag. Comparing to massive-star evolutionary tracks, we determine that the progenitor star had a maximum zero-age main sequence mass \\(<\\)17.5~M\\(_{\\odot}\\), consistent with other SN~II-P progenitor stars. SN\\,2019mhm can be added to the growing population of SNe~II-P with both direct constraints on the brightness of their progenitor stars and well-observed SN properties.

• Publisher: Cornell University Library, arXiv.org
• Subject: Explosions / Field cameras / Hubble Space Telescope / Light curve / Luminosity / Space telescopes / Wide field planetary camera