TITLE:   GCN CIRCULAR
NUMBER:  41039
SUBJECT: IceCube-250708A - IceCube observation of a high-energy neutrino candidate track-like event
DATE:    25/07/08 18:56:33 GMT
FROM:    A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>

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

On 25-07-08 at 14:05:19.54 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. 
The event was selected by the ICECUBE_Astrotrack_BRONZE alert stream.
The average astrophysical neutrino purity for Bronze alerts is 30%.
This alert has an estimated false alarm rate of 1.6259 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/141112_11292662.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 25-07-08
Time: 14:05:19.54 UT
RA: 222.71 (+0.52/-0.54 deg 90% PSF containment) J2000
Dec: 26.49 (+0.47/-0.47 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.

No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event.

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