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GCN Circular 33065

IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
2022-12-16T10:45:39Z (a year ago)
Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum <>
The IceCube Collaboration ( reports:

On 22-12-16 at 06:00:14.01 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 1.59 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: 22-12-16
Time: 06:00:14.01 UT

RA: 6.86 (+1.08/-2.06 deg  90% PSF containment) J2000
Dec: +10.43 (+1.54/-1.07 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. The nearest gamma-ray source in either catalog is 4FGL 
J0023.4+0920 at RA 5.85, dec +9.35 J2000, located 1.47 deg away from the 
best fit 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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