TITLE:   GCN CIRCULAR
NUMBER:  26341
SUBJECT: IceCube-191204A - IceCube observation of a high-energy neutrino candidate event
DATE:    19/12/05 00:39:59 GMT
FROM:    Robert Stein at DESY  <robert.stein@desy.de>

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

On 19/12/04 at 22:46:11.32 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 3.21 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/133394_27261780.amon <https://gcn.gsfc.nasa.gov/notices_amon_g_b/133394_27261780.amon>), more 
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 19/12/04 
Time: 22:46:11.32 UT
RA: 79.72 (+3.20 -1.74 deg 90% PSF containment) J2000
Dec: 2.80 (+1.12 -1.23 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 J0521.6+0103 at RA: 80.41 deg, Dec: 1.05 deg (1.88 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