GCN 45217: IceCube-260722A: Classification of ZTF26abjbxfs/SN 2026vts as a Type Ia Supernova

Robert Stein (UMD/JSI/NASA GSFC), Avinash Singh (Stockholm), and Jesper Sollerman (Stockholm) report:

We observed ZTF26abjbxfs / SN 2026vts, reported as a possible counterpart (Necker et al., GCN 45198) to IceCube-260722A (Zilleruelo Cañas et. al, GCN 45194). 

We obtained spectroscopic observations using the Alhambra Faint Object Spectrograph and Camera (ALFOSC) on the Nordic Optical Telescope (NOT), beginning at 2026-07-24 21:14:1 UTC. Data were reduced using PypeIt (Prochaska et al. 2020). 

The spectrum matches well to templates of a Type Ia supernova, and the transient is therefore unrelated to the neutrino. The spectrum is available on TNS.

The data presented here were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOT.