GCN Circular 31833

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

On 2022-04-05 at 04:57:26.12 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 3.28 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/136504_1833389.amon), more
sophisticated reconstruction algorithms have been applied offline, with
the direction refined to:

Date: 2022-04-05
Time:  04:57:26.12 UT
RA: +134.47 (+1.71/-1.72 deg  90% PSF containment) J2000
Dec: -1.27 (+1.45/-1.02 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-DR3 or 3FHL catalog sources in the 90%
uncertainty region. The nearest gamma-ray source in either catalog is
4FGL J0859.8+0053 at RA: 134.95 deg, Dec: 0.90 deg J2000 (2.22 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