Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 23605

IceCube-190104A - IceCube observation of a high-energy neutrino candidate event
2019-01-04T11:46:14Z (6 years ago)
Claudio Kopper at IceCube/U of Alberta <>
The IceCube Collaboration ( reports:

On January 4, 2019, IceCube detected a track-like, very-high-energy event with a high probability of being of astrophysical origin. The event was identified by the High Energy Starting Event (HESE) track selection. The IceCube detector was in a normal operating state. HESE tracks have a neutrino interaction vertex inside the detector and produce a muon that only partially traverses the detector volume, and have a high light level (a proxy for energy). An inspection of the event does not reveal any feature to rule out this event as an astrophysical candidate. However, this event has a light level that is right above the analysis threshold so there is a non-negligible probability that this event is an atmospheric background.

After the initial automated alert (, more 
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2019/01/04 
Time: 08:34:38.23 UT
RA: 357.98 [-2.1,+2.3] (deg  90% PSF containment) J2000
Dec: -26.65 [-2.5,+2.2] (deg 90% PSF containment) J2000

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
Looking for U.S. government information and services? Visit