TITLE:   GCN CIRCULAR
NUMBER:  28532
SUBJECT: IceCube-200929A: IceCube observation of a high-energy neutrino candidate event
DATE:    20/09/29 21:32:42 GMT
FROM:    Cristina Lagunas Gualda at DESY  <cristina.lagunas@desy.de>

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

On 20/09/29 at 17:48:36.84 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 1.411 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/134552_68615710.amon), more 
sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 20/09/29
Time: 17:48:36.84  UT
RA: 29.53 (+ 0.53 - 0.53  deg 90% PSF containment) J2000
Dec: 3.47 (+ 0.71 - 0.35  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 no Fermi-LAT 4FGL or 3FHL sources inside the 90% localization region. The closest source is 4FGL J0152.6+0147 located at RA 28.16 deg and Dec 1.79 deg (J2000), at a distance of 2.17 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