TITLE: GCN CIRCULAR NUMBER: 40280 SUBJECT: IceCube-250429A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 25/04/29 19:07:06 GMT FROM: Giacomo Sommani at Ruhr-Universität Bochum <gsommani@icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 25-04-29 at 15:23:15.63 UT IceCube detected a track-like event with a moderate 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 0.496 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/140870_26727884.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 25-04-29 Time: 15:23:15.63 UT RA: 59.68 (+0.47/-0.57 deg 90% PSF containment) J2000 Dec: 25.32 (+0.39/-0.44 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. No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event. 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/40280. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...