{
  "bibcode": "2023GCN.33337....1I",
  "body": "The IceCube Collaboration (http://icecube.wisc.edu/) reports:\n\nOn 2023-02-17 at 20:49:43.4 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 1.877 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/137661_22129736.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:\n\nDate: 2023-02-17\nTime:  20:49:43.4 UT\nRA: 124.54 (+1.67/-3.27  deg  90% PSF containment) J2000\nDec: 20.74 (+2.14/-2.46 deg 90% PSF containment) J2000\n\nWe encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.\n\nTwo gamma-ray sources listed in the 4FGL-DR3 Fermi-LAT catalog are located within the 90% error region of the candidate neutrino event. The sources are 4FGL J0816.9+2050 and 4FGL 4FGL J0817.1+1955, and are located 0.3 and 0.85 deg away from the best-fit position, respectively. The source 4FGL J0816.9+2050 is also listed in the Fermi 3FHL catalog as 3FHL J0816.9+2050.\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.",
  "circularId": 33337,
  "createdOn": 1676670947000,
  "email": "jmsantander@ua.edu",
  "subject": "IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event",
  "submitter": "Marcos Santander at U. Alabama/IceCube  <jmsantander@ua.edu>",
  "eventId": "IceCube-230217A"
}