GCN Circular 41338
Subject
IceCube-250813A - IceCube observation of a high-energy neutrino candidate track-like event
Event
Date
2025-08-13T08:05:29Z (6 days ago)
From
A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>
Via
Web form
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2025-08-13 03:21:09.69 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 2.0759 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 (https://gcn.gsfc.nasa.gov/notices_amon_g_b/141240_9390028.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2025-08-13
Time: 03:21:09.69 UT
RA: 275.36 (+0.84, -0.94 deg 90% PSF containment) J2000
Dec: 8.27 (+0.79, -0.75 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.
No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event.
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 roc@icecube.wisc.edu