TITLE: GCN CIRCULAR NUMBER: 31090 SUBJECT: IceCube-211116A: No neutrino counterpart detected with ANTARES DATE: 21/11/17 12:37:45 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Universite de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration. Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported bronze track event IceCube-211116A (GCN #31085 ). The reconstructed origin was 47 degrees below the horizon for ANTARES at the time of the alert. No muon neutrino candidate events were recorded within 90% error box of the IceCube event during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible with a limited lifetime of ~50% due to acquisition instabilities. This leads to a preliminary 90% confidence level upper limit on the muon-neutrino radiant fluence from a point source of about 16 GeV.cm^-2 over the energy range 3 TeV –3.5 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 26 GeV.cm^-2 (640 GeV - 320 TeV) for an E^-2.5 spectrum. A search over an extended time window of +/- 1 day has also yielded no detection (50% visibility with ~40% lifetime). ANTARES is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky.