AT 2024ahzi: A Type IIP Supernova Discovered by the LSST Commissioning Camera

TL;DR

This paper reports the discovery and photometric classification of a Type IIP supernova by the Vera C. Rubin Observatory's commissioning camera, demonstrating a workflow for future supernova identification and analysis.

Contribution

It introduces a method for classifying and analyzing SNe II using early data from the Rubin Observatory's ComCam and DECam, including progenitor and explosion constraints.

Findings

AT 2024ahzi is consistent with typical SNe IIP in light curve and color.

Constraints on progenitor and circumstellar environment were derived.

The workflow can be applied to future Rubin SNe II discoveries.

Abstract

As part of its commissioning, the Vera C. Rubin Observatory observed several fields repeatedly for a month with ComCam, an instrument that uses the same hardware as the LSST camera but covers a smaller field of view. We photometrically classify AT 2024ahzi, a transient discovered by ComCam, as a Type IIP supernova (SN IIP) using both ComCam and DECam photometry. We find that the duration, luminosity, and color of AT 2024ahzi's photometric plateau are all consistent with those from a large sample of SNe II. By comparing its multi-band light curves to SN II models and analytic relations, we place constraints on the SN progenitor, explosion dynamics, and circumstellar environment. We argue that the progenitor has an extended density profile indistinguishable from a slowly accelerating CSM. We discuss how a similar workflow can identify and characterize future Rubin SNe II.