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GCN Circular 33204

IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
2023-01-22T05:24:48Z (a year ago)
Erik Blaufuss at U. Maryland/IceCube <>
The IceCube Collaboration ( reports:

On 2023-01-22 03:50:02.00 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 3.62 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 (, more  
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2023-01-22
Time:  03:50:02.00 UT
RA:16.79 (+3.17 / -2.56 deg  90% PSF containment) J2000
Dec: +7.78 (+3.44 / -3.26 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 four known gamma-ray sources listed in the Fermi 4FGL catalog within the 90% uncertainty region of the event. The nearest one is 4FGL J0100.3+0745 (RA: 15.09 deg, Dec: 7.76 deg in J2000 coordinates), 1.68 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
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