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GCN Circular 33097

IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
2022-12-24T04:04:09Z (a year ago)
Marcos Santander at U. Alabama/IceCube <>
The IceCube Collaboration ( reports:

On 2022-12-24 at 00:55:09.3 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 4.116 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: 2022-12-24
Time:  00:55:09.3 UT
RA: 335.74 (+1.01, -0.72 deg  90% PSF containment) J2000
Dec: 1.42 (+0.41, -0.30 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 or 3FHL catalog sources in the 90% uncertainty region of the event. The nearest gamma-ray source in either catalog is 4FGL J2223.3+0102 at RA: 335.85 deg, Dec: 1.05 deg J2000 (0.39 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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