TITLE:   GCN CIRCULAR
NUMBER:  23214
SUBJECT: IceCube-180908A - IceCube observation of a high-energy neutrino candidate event
DATE:    18/09/09 02:49:16 GMT
FROM:    Erik Blaufuss at U. Maryland/IceCube  <blaufuss@umd.edu>

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

On September 8, 2018, IceCube detected a track-like, very-high-energy event with a high probability of being of astrophysical origin. The event was identified by the  Extremely High Energy (EHE) track event selection. The IceCube detector was in a normal operating state.  EHE events typically have a neutrino interaction vertex that is outside the detector, produce a muon that traverses the detector volume, and have a high light level (a proxy for energy). 

After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon/34507973_131475.amon), more 
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 18/09/08 
Time: 19:59:31.84 UT
RA: 144.58 [-1.45,+1.55] (deg  90% PSF containment) J2000
Dec: -2.13 [-1.2,+0.9] (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.

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