TITLE: GCN CIRCULAR NUMBER: 25582 SUBJECT: GRB 190829A: No Neutrino Counterpart detected with ANTARES DATE: 19/08/30 20:49:41 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Univ de Paris) and Damien Dornic (CPPM/CNRS) report on behalf of the ANTARES Collaboration: Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported GRB 190829A (Fermi-GBM GCN 25551, Swift GCN 25552) also observed in TeV gamma-rays ( H.E.S.S GCN 25566). No up-going muon neutrino candidate events were detected within 3 degrees of the GRB coordinates during a +/- 1h time-window centered on the time of the Swift Burst Alert, and over which the potential source remained visible all time. A search over an extended time window of +1 day has also yielded no detection (55% visibility). This leads to a preliminary 90% confidence level upper limit on the muon-neutrino radiant fluence from a point source of about 15 GeV.cm^-2 over the energy range 3 TeV – 3 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 30 GeV.cm^-2 (500 GeV - 250 TeV) for an E^-2.5 spectrum, computed for the time of the Swift Burst Alert. 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.