SN 2022acko and the Properties of Its Red Supergiant Progenitor: Direct Detection, Light Curves, and Nebular Spectroscopy

Abstract

Abstract We present ultraviolet, optical, and infrared observations of the Type II-P supernova SN 2022acko in NGC 1300, located at a distance of 19.0 ± 2.9 Mpc. Our dataset spans 1–350 day postexplosion in photometry, complemented by late-time optical spectroscopy covering 200–600 days, and includes deep preexplosion imaging. We use this extensive multiwavelength dataset for both direct and indirect constraints on the progenitor system. Using the early time photometry and shock cooling models, we infer that SN 2022acko likely originated from a red supergiant with a radius of R  ∼ 580 R ..