TITLE: GCN CIRCULAR NUMBER: 34163 SUBJECT: IceCube-230707A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 23/07/07 18:14:43 GMT FROM: Massimiliano Lincetto at Ruhr-Universitaet Bochum The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 23-07-07 at 16:58:50.03 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.4443 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/138125_11333473.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 23-07-07 Time: 16:58:50.03 UT RA: 269.03 (+0.88 / -0.76 deg 90% PSF containment) J2000 Dec: -1.94 (+0.53 / -0.54 deg 90% PSF containment) J2000 We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. There are no Fermi 4FGL-DR3 or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J1759.0-0107 at RA: 269.77 deg, Dec: -1.12 deg (1.10 deg away from the best-fit event position). The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu