TITLE:   GCN CIRCULAR
NUMBER:  26276
SUBJECT: IceCube-191122A - IceCube observation of a high-energy neutrino candidate event
DATE:    19/11/23 00:35:12 GMT
FROM:    Erik Blaufuss at U. Maryland/IceCube  <blaufuss@umd.edu>

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


On Nov 22, 2019  at 22:45:10.50 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 
threshold astrophysical neutrino purity for Bronze alerts is 30%. This 
alert has an estimated false alarm rate of 3.099 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/133348_80807014.amon), more
sophisticated reconstruction algorithms have been applied offline, with 
the direction refined to:

Date: 19/11/22 (yy/mm/dd)
Time: 22:45:10.50 UT
RA: 27.25 (+1.70/-2.90 deg - 90% PSF containment) J2000
Dec: -0.04 (+1.17/-1.49 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 
J0148.6+0127 at RA: 27.16 deg, Dec: 1.46 deg (1.51 deg away from the 
best-fit event position, in J2000 coordinates). This source is also 
listed as 3FHL J0148.6+0127    and is associated with the BL Lac object 
PMN J0148+0129.


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