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This content will become publicly available on March 11, 2026

Title: Luminous Type II Short-plateau SN 2023ufx: Asymmetric Explosion of a Partially Stripped Massive Progenitor
Abstract We present supernova (SN) 2023ufx, a unique Type IIP SN with the shortest known plateau duration (tPT∼ 47 days), a luminousV-band peak (MV= −​​​​​​18.42 ± 0.08 mag), and a rapid early decline rate (s1 = 3.47 ± 0.09 mag (50 days)−1). By comparing observed photometry to a hydrodynamic MESA+STELLA model grid, we constrain the progenitor to be a massive red supergiant withMZAMS∼ 19–25M⊙. Independent comparisons with nebular spectral models also suggest an initial He-core mass of ∼6M⊙, and thus a massive progenitor. For a Type IIP, SN 2023ufx produced an unusually high amount of nickel (56Ni) ∼0.14 ± 0.02M⊙, during the explosion. We find that the short plateau duration in SN 2023ufx can be explained with the presence of a small hydrogen envelope ( M H env ∼ 1.2M⊙), suggesting partial stripping of the progenitor. About ∼0.09M⊙of circumstellar material through mass loss from late-time stellar evolution of the progenitor is needed to fit the early time (≲10 days) pseudo-bolometric light curve. Nebular line diagnostics of broad and multipeak components of [Oi]λλ6300, 6364, Hα, and [Caii]λλ7291, 7323 suggest that the explosion of SN 2023ufx could be inherently asymmetric, preferentially ejecting material along our line of sight.  more » « less
Award ID(s):
2407566 2407565 2407567
PAR ID:
10628752
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publisher / Repository:
AAS Journals
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
982
Issue:
1
ISSN:
0004-637X
Page Range / eLocation ID:
12
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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