TITLE:   GCN CIRCULAR
NUMBER:  28465
SUBJECT: IceCube-200916A - ZTF20acaapwk/SN2020tno classified as SN Ia
DATE:    20/09/21 14:30:23 GMT
FROM:    Simeon Reusch at DESY  <simeon.reusch@desy.de>

Simeon Reusch, Robert Stein, Anna Franckowiak (DESY), Steve Schulze (WIS) and Jesper Sollerman (Stockholm University) report:

We observed ZTF candidate ZTF20acaapwk/SN2020tno (Reusch et al., GCN 28441; see also Belkin et al., GCN 28453), a possible counterpart to high-energy neutrino IceCube-200916A (Blaufuss, GCN 28433), using the NOT+ALFOSC spectrograph on 21 September 2020.

We classify SN2020tno as a type Ia supernova, thereby excluding any connection to IC200916A.

ZTF20acaapwo/AT2020tnp remains a candidate.

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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 NOTSA.