GCN Circular 29454

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

On 21/02/10 at 11:53:55.65 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 0.464 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/134979_17138286.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 21/02/10
Time: 11:53:55.65 UT
RA: 206.06 (+ 1.40 - 0.95 deg 90% PSF containment) J2000
Dec: 4.78 (+ 0.62 - 0.56 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 is one Fermi-LAT 4FGL source inside the 90% localization region, 4FGL J1342.7+0505, located at RA 205.69 deg and Dec 5.09 deg (J2000), at a distance of 0.49 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 roc@icecube.wisc.edu