TITLE: GCN CIRCULAR NUMBER: 20709 SUBJECT: LIGO/Virgo G274296: IceCube neutrino observations DATE: 17/02/20 21:46:28 GMT FROM: Imre Bartos at Columbia/LIGO I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. Blaufuss (U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on behalf of the IceCube Collaboration We searched IceCube online track-like neutrino candidates (GFU) detected in a [-500,500] second interval about the LIGO-Virgo trigger G274296. We compared the candidate source directions of 3 temporally-coincident neutrinos to the cWB skymap, with the following parameters: # dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg] -------------------------------------------- 1. -279 136.6 20.8 9.55 1.7 2. -134 299.3 14.3 10.53 0.6 3. 228 9.8 7.7 5.36 0.4 The analysis found NO COINCIDENT ONLINE TRACK-LIKE NEUTRINO CANDIDATES detected by IceCube within the 500 second window surrounding G274296 within the cWB skymap. In addition, we performed coincident searches with other IceCube data streams, including the high-energy starting events (HESE) and Supernova triggers. HESE events have typical energies > 60 TeV and start inside the detector volume, leading to a relatively pure event sample with a high fraction of astrophysical neutrinos. The SN trigger system is sensitive to sudden increases in photomultiplier counts across the detector, which could indicate a burst of MeV neutrinos. NO COINCIDENT HESE OR SUPERNOVA SIGNATURES were identified by these searches. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. For a description of the IceCube realtime alert system, please refer to; for more information on joint neutrino and gravitational wave searches, please refer to.