TITLE:   GCN CIRCULAR
NUMBER:  33567
SUBJECT: IceCube-230405A: IceCube observation of a high-energy neutrino candidate
DATE:    23/04/05 15:35:21 GMT
FROM:    Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum  <lincetto@astro.rub.de>

On 2023-04-05 at 13:20:20.04 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 2.84 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/137806_8756840.amon), more
sophisticated reconstruction algorithms have been applied offline, with
the direction refined to:

Date: 2023-04-05
Time: 13:20:20.04 UT
RA: 120.85 (+2.86 / -4.98 deg 90% PSF containment) J2000
Dec: +9.75 (+1.87 / -2.17 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.

Six gamma-ray sources listed in the 4FGL-DR3 Fermi-LAT catalog are
located within the 90% containment radius of the event. The nearest
source is 4FGL J0802.0+1006 located at RA 120.51 deg, Dec 10.11 deg
J2000, 0.49 deg away from the best-fit 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