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

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 ≈1000 days and an amplitude of Δm≈ 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-IRJandKsbands 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. The IR brightness (MKs=10.7mag) and color (JKs= 1.6 mag) of the star suggest a luminous and dusty red supergiant. Modeling of the phase-averaged spectral energy distribution (SED) yields constraints on the stellar temperature (Teff=35001400+800K) and luminosity (logL/L=5.1±0.2). This places the candidate among the most luminous Type II supernova progenitors with direct imaging constraints, with the caveat that many of these rely only on optical measurements. Comparison with stellar evolution models gives an initial mass ofMinit= 17 ± 4M. We estimate the pre-supernova mass-loss rate of the star between 3 and 19 yr before explosion from the SED modeling atṀ3×105to 3 × 10−4Myr−1for an assumed wind velocity ofvw= 10 km s−1, perhaps pointing to enhanced mass loss in a pulsation-driven wind.

 
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Award ID(s):
2008108 1813466
NSF-PAR ID:
10437528
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; « less
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal Letters
Volume:
952
Issue:
2
ISSN:
2041-8205
Format(s):
Medium: X Size: Article No. L30
Size(s):
["Article No. L30"]
Sponsoring Org:
National Science Foundation
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