GCN Circular 27865

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

On 20/05/30 at 07:54:29.43 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 threshold astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 1.952 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 (https://gcn.gsfc.nasa.gov/notices_amon_g_b/134139_35473338.amon), more  
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 20/05/30
Time:  07:54:29.43 UT
RA: 255.37 (+2.48 -2.56 deg  90% PSF containment) J2000
Dec: 26.61  (+2.33 -3.28 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 two Fermi 4FGL catalogue sources within the 90% contour, both lying close to the best fit position. The nearest is 4FGL J1702.2+2642, located 0.20 degrees from the best fit position. The other, 4FGL J1659.0+2627, is located 0.56 degrees from the best fit.

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