Evidence of Weak Circumstellar Medium Interaction in the Type II SN 2023axu

Manisha Shrestha, Jeniveve Pearson, Samuel Wyatt, David J. Sand, Griffin Hosseinzadeh, K. Azalee Bostroem, Jennifer E. Andrews, Yize Dong, Emily Hoang, Daryl Janzen, Jacob E. Jencson, Michael Lundquist, Darshana Mehta, Nicolás Meza Retamal, Stefano Valenti, Jillian C. Rastinejad, Phil Daly, Dallan Porter, Joannah Hinz, Skyler SelfBenjamin Weiner, G. Grant Williams, Daichi Hiramatsu, D. Andrew Howell, Curtis McCully, Estefania Padilla Gonzalez, Craig Pellegrino, Giacomo Terreran, Megan Newsome, Joseph Farah, Koichi Itagaki, Saurabh W. Jha, Lindsey Kwok, Nathan Smith, Michaela Schwab, Jeonghee Rho, Yi Yang

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


We present high-cadence photometric and spectroscopic observations of SN 2023axu, a classical Type II supernova with an absolute V-band peak magnitude of -17.2 ± 0.1 mag. SN 2023axu was discovered by the Distance Less Than 40 Mpc (DLT40) survey within 1 day of the last nondetection in the nearby galaxy NGC 2283 at 13.7 Mpc. We modeled the early light curve using a recently updated shock cooling model that includes the effects of line blanketing and found the explosion epoch to be MJD 59971.48 ± 0.03 and the probable progenitor to be a red supergiant. The shock cooling model underpredicts the overall UV data, which point to a possible interaction with circumstellar material. This interpretation is further supported by spectral behavior. We see a ledge feature around 4600 Å in the very early spectra (+1.1 and +1.5 days after the explosion), which can be a sign of circumstellar interaction. The signs of circumstellar material are further bolstered by the presence of absorption features blueward of Hα and Hβ at day >40, which is also generally attributed to circumstellar interaction. Our analysis shows the need for high-cadence early photometric and spectroscopic data to decipher the mass-loss history of the progenitor.

Original languageEnglish (US)
Article number247
JournalAstrophysical Journal
Issue number2
StatePublished - Feb 1 2024

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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