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GCN Circular 34891

IceCube-231027A - IceCube observation of a high-energy neutrino candidate track-like event
2023-10-27T12:48:52Z (6 months ago)
Massimiliano Lincetto at Ruhr-Universitaet Bochum <>
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The IceCube Collaboration ( reports:

On 23-10-27 at 04:16:10.44 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 0.1472 events per year due to atmospheric
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: 23-10-27
Time: 04:16:10.44 UT
RA: 267.16 (+3.35/-3.40 deg 90% PSF containment) J2000
Dec: +46.96 (+2.25/-2.88 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.

Seven gamma-ray sources listed in the 4FGL-DR3 Fermi-LAT catalog are located in the 90% containment region. The closest source is 4FGL J1747.9+4704 at RA 266.99, Dec +47.07, 0.16 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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