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GCN Circular 26276

IceCube-191122A - IceCube observation of a high-energy neutrino candidate event
2019-11-23T00:35:12Z (5 years ago)
Erik Blaufuss at U. Maryland/IceCube <>
The IceCube Collaboration ( 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 
(, 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
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