Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 23785

IceCube-190124A - IceCube observation of a high-energy neutrino candidate event
2019-01-24T14:51:17Z (5 years ago)
Erik Blaufuss at U. Maryland/IceCube <>
The IceCube Collaboration ( reports:

On January 24, 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.

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

Date: 2019/01/24
Time: 03:43:54.79 UT
RA: 307.40 [-0.9,+0.8] (deg  90% PSF containment) J2000
Dec: -32.18 [-0.7,+0.7] (deg 90% PSF containment) J2000

Within the 90% containment region there are no 3FGL or 3FHL objects. We encourage follow-up of this alert by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.

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

Erik Blaufuss                      email:
Department of Physics
University of Maryland       Phone: 301-405-6077
College Park, MD 20742   Office: PSC 2208E
"Any chance collision, and I light up in the dark."
Looking for U.S. government information and services? Visit