GCN Circular 36918

The IceCube Collaboration (http://icecube.wisc.edu/) reports:

On 2024-07-21 at 16:17:25.8 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 1.376 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/139674_30853199.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2024-07-21
Time:  16:17:25.8 UT
RA: 354.99 (+1.08, -1.14 deg 90% PSF containment) J2000
Dec: 22.67 (+1.38, -1.14 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-DR4 or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J2338.9+2124 at RA: 354.74 deg, Dec: 21.40 deg J2000 (1.29 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 roc@icecube.wisc.edu