The quiescent progenitors of four Type II-P/L supernovae

TL;DR

This study uses difference imaging to analyze four Type II-P/L supernova progenitors, finding no significant variability and constraining the likelihood of extended outbursts before explosion.

Contribution

First systematic variability constraints on multiple Type II-P/L supernova progenitors using difference imaging data.

Findings

No significant variability detected in progenitors.

Limits on variability are comparable to those of red supergiants.

Probability of extended outbursts before explosion is less than 37%.

Abstract

We present Large Binocular Telescope difference imaging data for the final years of four Type II-P/L supernovae progenitors. For all four, we find no significant evidence for stochastic or steady variability in the U, B, V, or R-bands. Our limits constrain variability to no more than roughly 5-10% of the expected R-band luminosities of the progenitors. These limits are comparable to the observed variability of red supergiants in the Magellanic Clouds. Based on these four events, the probability of a Type II-P/L progenitor having an extended outburst after Oxygen ignition is <37% at 90% confidence. Our observations cannot exclude short outbursts in which the progenitor returns to within ~10% of its quiescent flux on the time scale of months with no dust formation.