GCN Circular 26655

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

On 20/01/07 at 09:42:18.36 UT IceCube detected a high-energy starting event [1]. Though it did not pass the Gold or Bronze starting track classification, a new neural network classifier identified the event as a starting track. Visual inspection is consistent with this classification. High-energy starting events have a rate of ~12 per year, out of which ~2 per year are starting tracks. Because the event was not identified as either Gold or Bronze, we do not currently report a false alert rate or signalness. However, given the topology and light deposition of this event, we identify it as a potential astrophysical neutrino of interest to the community. The IceCube detector was in a normal operating state at the time of detection. 

Sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 20/01/07
Time: 09:42:18.36  UT
RA: 148.18 (+ 2.20 - 1.83 deg 90% PSF containment) J2000
Dec:  35.46 (+ 1.10 - 1.22 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 sources located within the 90% localization region. The nearest gamma-ray source is 4FGL J0955.1+3551 at RA: 148.78 deg, Dec: 35.86 deg (0.63 deg away from the best-fit event position). Another source, 4FGL J0957.8+3423, is located at RA: 149.47 deg, Dec: 34.40 (1.50 deg away from the best-fit event position).

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 <mailto:roc@icecube.wisc.edu>
[1] The IceCube Collaboration, Phys. Rev. Lett. 113, 101101 (2014)