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GCN Circular 34693

IceCube-230914A - IceCube observation of a high-energy neutrino candidate track-like event
2023-09-14T12:41:38Z (7 months ago)
Massimiliano Lincetto at Ruhr-Universitaet Bochum <>
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The IceCube Collaboration ( reports:

On 2023-09-14 at 05:21:03.71 UT IceCube detected a track-like event with a high 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 0.8823 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: 2023-08-23
Time:  05:21:03.71 UT
RA: 163.83 (+2.60 / -2.02 deg  90% PSF containment) J2000
Dec: +31.83 (+1.79 / - 2.13 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.

Two Fermi 4FGL-DR4 sources are located in the 90% uncertainty region of the event. The sources are 4FGL J1051.6+3253 (NGC 3434) at RA 162.91, Dec +32.88 and 4FGL J1102.9+3014 at RA 165.74, Dec +30.24, located 1.31 and 2.28 deg away from the best fit position, respectively.

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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