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GCN Circular 29012

IceCube-201209A: IceCube observation of a high-energy neutrino candidate event
2020-12-09T14:00:14Z (3 years ago)
Cristina Lagunas Gualda at DESY <>
The IceCube Collaboration ( reports:

On 20/12/09 at 10:15:43.94 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream.  The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.77 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.

Due to a technical problem, the initial automated alert was not issued. Nonetheless, sophisticated reconstruction algorithms have been applied offline, with a direction of:

Date: 20/12/09
Time: 10:15:43.94 UT
RA: 6.86 (+ 1.02 - 1.22 deg  90% PSF containment) J2000
Dec: -9.25 (+ 0.99 - 1.14 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-LAT 4FGL or 3FHL sources inside the 90% localization region. The closest source is 4FGL J0021.6-0855 located at RA 5.41 deg and Dec -8.92 deg (J2000), at a distance of 1.47 degrees from the best-fit location.

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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