The Astrophysical Journal (Jan 2025)

Luminous Type II Short-plateau SN 2023ufx: Asymmetric Explosion of a Partially Stripped Massive Progenitor

  • Aravind P. Ravi,
  • Stefano Valenti,
  • Yize Dong,
  • Daichi Hiramatsu,
  • Stan Barmentloo,
  • Anders Jerkstrand,
  • K. Azalee Bostroem,
  • Jeniveve Pearson,
  • Manisha Shrestha,
  • Jennifer E. Andrews,
  • David J. Sand,
  • Griffin Hosseinzadeh,
  • Michael Lundquist,
  • Emily Hoang,
  • Darshana Mehta,
  • Nicolás Meza Retamal,
  • Aidan Martas,
  • Saurabh W. Jha,
  • Daryl Janzen,
  • Bhagya Subrayan,
  • D. Andrew Howell,
  • Curtis McCully,
  • Joseph Farah,
  • Megan Newsome,
  • Estefania Padilla Gonzalez,
  • Giacomo Terreran,
  • Moira Andrews,
  • Alexei V. Filippenko,
  • Thomas G. Brink,
  • Weikang Zheng,
  • Yi Yang,
  • Jozsef Vinkó,
  • J. Craig Wheeler,
  • Nathan Smith,
  • Jeonghee Rho,
  • Réka Könyves-Tóth,
  • Claudia P. Gutiérrez

DOI
https://doi.org/10.3847/1538-4357/adb0bb
Journal volume & issue
Vol. 982, no. 1
p. 12

Abstract

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We present supernova (SN) 2023ufx, a unique Type IIP SN with the shortest known plateau duration ( t _PT ∼ 47 days), a luminous V -band peak ( M _V = −​​​​​​18.42 ± 0.08 mag), and a rapid early decline rate ( s 1 = 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 with M _ZAMS ∼ 19–25 M _⊙ . Independent comparisons with nebular spectral models also suggest an initial He-core mass of ∼6 M _⊙ , and thus a massive progenitor. For a Type IIP, SN 2023ufx produced an unusually high amount of nickel ( ^56 Ni) ∼0.14 ± 0.02 M _⊙ , during the explosion. We find that the short plateau duration in SN 2023ufx can be explained with the presence of a small hydrogen envelope ( ${M}_{{{\rm{H}}}_{\mathrm{env}}}$ ∼ 1.2 M _⊙ ), suggesting partial stripping of the progenitor. About ∼0.09 M _⊙ 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 [O i ] λλ 6300, 6364, H α , and [Ca ii ] λλ 7291, 7323 suggest that the explosion of SN 2023ufx could be inherently asymmetric, preferentially ejecting material along our line of sight.

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