{
  "circularId": 39549,
  "bibcode": "2025GCN.39549....1I",
  "eventId": "IceCube-250302A",
  "submittedHow": "web",
  "createdOn": 1740931440158,
  "format": "text/plain",
  "submitter": "A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>",
  "body": "The IceCube Collaboration (http://icecube.wisc.edu/) reports:\n\nOn 2025-03-02 at 03:20:52.90 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 0.1579 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.\n\nAfter the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/140601_60511904.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:\n\nDate: 2025-03-02\nTime:  03:20:52.90 UT\nRA: 348.05 (+0.38 -0.43 deg  90% PSF containment) J2000\nDec: 3.77 (+0.42 -0.41 deg 90% PSF containment) J2000\n\nNo known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event.\n\nHowever, given the particularly high signalness (~97%) and energy (~1.5 PeV) of this event, we strongly encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.\n\nThe 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",
  "subject": "IceCube-250302A - IceCube observation of a high-energy neutrino candidate track-like event"
}