GCN Circular 31543

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

On 2022-02-02 at 11:48:38.59 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 1.925 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/136241_22093816.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2022-02-02 
Time: 11:48:38.59 UTC
RA: 21.36 (+1.10, -0.77 deg  90% PSF containment) J2000
Dec: -3.88 (+0.42, -0.64 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 or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J0124.8-0625 at RA: 21.22 deg, Dec: -6.43 deg (2.56 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