One Year of SN 2023ixf: Breaking through the Degenerate Parameter Space in Light-curve Models with Pulsating Progenitors

We present and analyze the extensive optical broadband photometry of the Type II SN 2023ixf up to 1 yr after explosion. We find that, when compared to two preexisting model grids, the bolometric light curve is consistent with drastically different combinations of progenitor and explosion properties. This may be an effect of known degeneracies in Type IIP light-curve models. We independently compute a large grid of MESA+STELLA single-star progenitor and light-curve models with various zero-age main-sequence masses, mass-loss efficiencies, and convective efficiencies. Using the observed progenitor variability as an additional constraint, we select stellar models consistent with the pulsation period and explode them according to previously established scaling laws to match plateau properties. Our hydrodynamic modeling indicates that SN 2023ixf is most consistent with a moderate-energy ( E exp ≈ 7 × 1 0 50 erg) explosion of an initially high-mass red supergiant progenitor (≳16.5 M ⊙ ) that lost a significant amount of mass in its prior evolution, leaving a low-mass hydrogen envelope (≲3 M ⊙ ) at the time of explosion, with a radius ≳950 R ⊙ and a synthesized 56 Ni mass of ≈0.068 M ⊙ . We posit that previous mass transfer in a binary system may have stripped the envelope of SN 2023ixf’s progenitor. The analysis method with pulsation period presented in this work offers a way to break degeneracies in light-curve modeling in the future, particularly with the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time, when a record of progenitor variability will be more common.