A Luminous Red Supergiant and Dusty Long-period Variable Progenitor for SN 2023ixf

Understand

We analyze pre-explosion near- and mid-infrared (IR) imaging of the site of SN 2023ixf in the nearby spiral galaxy M101 and characterize the candidate progenitor star.

• The star displays compelling evidence of variability with a possible period of $\approx$1000 days and an amplitude of $\Delta m \approx 0.6$ mag in extensive monitoring with the Spitzer Space Telescope since 2004, likely indicative of radial pulsations.
• Variability consistent with this period is also seen in the near-IR $J$ and $K_{s}$ bands between 2010 and 2023, up to just 10 days before the explosion.
• Beyond the periodic variability, we do not find evidence for any IR-bright pre-supernova outbursts in this time period.