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GCN Circular 27980

IceCube-200530A - SN2020lls likely unrelated
2020-06-18T13:53:49Z (4 years ago)
Simeon Reusch at DESY <>
Simeon Reusch, Robert Stein, Anna Franckowiak, Jannis Necker (DESY),
Jesper Sollerman, Cristina Barbarino and Tassilo Schweyer (Stockholm
University) report:

We observed ZTF candidate SN2020lls (Reusch et al, GCN 27872), a
possible counterpart to high-energy neutrino IceCube-200530A (Stein et.
al, GCN 27865), using the NOT/ALFOSC spectrograph on 12 June 2020.

We classify SN2020lls as a Type Ic supernova without broad-line features.

SN2020lls was detected with forced photometry by ZTF in i-band images 1
day prior to neutrino detection. An explosion time estimator puts the
supernova explosion time 8 (+5/-2) days prior to neutrino detection.
Both points suggest that the neutrino was detected several days after
explosion. ��

The apparent delay between supernova explosion and neutrino detection is
inconsistent with a choked-jet neutrino production scenario. Therefore,
SN2020lls is likely not related to the high-energy IceCube neutrino

AT2019fdr remains a source candidate.
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