On the progenitor and early evolution of the type II supernova 2009kr

TL;DR

This paper identifies a potential yellow supergiant progenitor for SN 2009kr in pre-explosion images and discusses its properties, early lightcurve, and spectral peculiarities to understand the supernova's origins.

Contribution

It provides the first identification of a progenitor candidate for SN 2009kr and analyzes its characteristics and early supernova features, offering insights into its progenitor's nature.

Findings

Progenitor likely a yellow supergiant of about 15 solar masses.

Early lightcurve is flat, similar to Type IIP supernovae.

Spectra show unusual P-Cygni profiles, indicating peculiar ejecta evolution.

Abstract

We report the identification of a source coincident with SN 2009kr in HST pre-explosion images. The object appears to be a single point source with an intrinsic colour V-I = 1.1 and M_V = -7.6. If this is a single star it would be a yellow supergiant of log L/L_{sol} \sim 5.1 and a mass of 15 (+5/-4) M_{sol}. The spatial resolution does not allow us yet to definitively determine if the progenitor object is a single star, a binary system, or a compact cluster. We show that the early lightcurve is flat, similar to IIP SNe, but that the the spectra are somewhat peculiar, displaying unusual P-Cygni profiles. The evolution of the expanding ejecta will play an important role in understanding the progenitor object.