Seeking Core-Collapse Supernova Progenitors in Pre-Explosion Images

TL;DR

This paper reviews how pre-explosion imaging has advanced understanding of the progenitors of various core-collapse supernovae, comparing observational constraints with stellar evolution models to infer their physical properties.

Contribution

It provides a comprehensive review of methods and findings in identifying and constraining supernova progenitors from pre-explosion images across different supernova types.

Findings

Progenitor stars have been directly measured or constrained for nearly three dozen supernovae.

SN 2005gl had an extremely luminous, very massive progenitor, challenging standard models.

Different supernova types show diverse progenitor characteristics and evolutionary histories.

Abstract

I summarize what we have learned about the nature of stars that ultimately explode as core-collapse supernovae from the examination of images taken prior to the explosion. By registering pre-supernova and post-supernova images, usually taken at high resolution using either space-based optical detectors, or ground-based infrared detectors equipped with laser guide star adaptive optics systems, nearly three dozen core-collapse supernovae have now had the properties of their progenitor stars either directly measured or (more commonly) constrained by establishing upper limits on their luminosities. These studies enable direct comparison with stellar evolution models that, in turn, permit estimates of the progenitor stars' physical characteristics to be made. I review progenitor characteristics (or constraints) inferred from this work for each of the major core-collapse supernova types (II-Plateau, II-Linear, IIb, IIn, Ib/c), with a particular focus on the analytical techniques used and the processes through which conclusions have been drawn. Brief discussion of a few individual events is also provided, including SN 2005gl, a type IIn supernova that is shown to have had an extremely luminous -- and thus very massive -- progenitor that exploded shortly after a violent, luminous blue variable-like eruption phase, contrary to standard theoretical predictions.