Shock-cooling Constraints via Early-time Observations of the Type IIb SN 2022hnt

TL;DR

This study analyzes early light curves of the Type IIb supernova 2022hnt to constrain progenitor properties using shock-cooling models, providing a framework for future progenitor and explosion property studies.

Contribution

It introduces a comprehensive framework for applying shock-cooling models to Type IIb supernovae and applies recent models to SN 2022hnt, including the first use of the Morag2023 model for this SN type.

Findings

Progenitor radii estimated between 50 and 100 solar radii.

Hydrogen envelope masses between 0.01 and 0.1 solar masses.

Consistent properties with other Type IIb supernovae.

Abstract

We report the results of a rapid follow-up campaign on the Type IIb Supernova (SN) 2022hnt. We present a daily, multi-band, photometric follow-up using the Las Cumbres Observatory, the Zwicky Transient Facility, the orbiting \textit{Swift} observatory, and the Asteroid Terrestrial-impact Last Alert System (ATLAS). A distinctive feature in the light curve of SN 2022hnt and other IIb SNe is an early narrow peak prior to the ${}^{56}$Ni peak caused by rapid shock cooling of the hydrogen envelope, which can serve as an important probe of the properties of the massive progenitor star in the moments before explosion. Using SN 2022hnt as a case study, we demonstrate a framework of considerations for the application of shock cooling models to type IIb SNe, outlining a consistent procedure for future surveys of Type IIb SNe progenitor and explosion properties. \hll{We fit several recent models of shock-cooling emission and obtain progenitor radii between $\sim50$ and $\sim100$ $R_\odot$, as well as hydrogen-enriched envelope masses between $\sim0.01$ and $\sim0.1$ $M_\odot$, both consistent with values for other IIb SNe. One of these models is the model of \cite{Morag2023}, marking the first time this model has been applied to a Type IIb SN.} We evaluate contrasting predictions between shock-cooling models to construct a fiducial parameter set which can be used for comparison to other SNe. Finally, we investigate the possibility of extended wind breakout or precursor emission captured in the earliest detections.