GCN Circular 33354

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

On 2023-02-20 at 07:39:10.8 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 2.521 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/137668_51133257.amon), 
attempts to use a more sophisticated algorithm that provides refined 
position and error estimates encountered issues.
Given the topology of the light deposition in the detector, we estimate 
that the initial direction listed below still provides a good 
characterization of the event.

Date: 2023-02-20
Time:  07:39:10.8 UT
RA: 359.33 deg (J2000)
Dec: +3.35 deg (J2000)
Error radius: 0.51 deg (90%, statistical error only)

We encourage follow-up by ground and space-based instruments to help 
identify a possible astrophysical source for the candidate neutrino.

No gamma-ray sources listed in the 4FGL-DR3 or 3FHL Fermi-LAT catalogs 
are located within the 90% error radius of the candidate neutrino event.
The nearest source is 4FGL J2359.3+0215, 1.2 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