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GCN Circular 33122

IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
2022-12-29T15:01:36Z (a year ago)
Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum <>
The IceCube Collaboration ( reports:

On 2022-12-29 at 07:25:27.88 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 1.014 events per year
due to atmospheric backgrounds.
The IceCube detector was in a normal operating state at the time of

After the initial automated alert
(, more
sophisticated reconstruction algorithms have been applied offline, with
the direction refined to:

Date: 2022-12-29
Time: 07:25:27.88 UT
RA: 31.90 (+1.68/-1.55 deg 90% PSF containment) J2000
Dec: +4.18 (+1.39/-0.84 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 J0215.9+0521 (TXS 0213+051) at RA: 33.99 deg, Dec: 5.35 deg J2000
(2.39 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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