Multiwavelength follow-up of a rare IceCube neutrino multiplet

Understand

On February 17 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky.

• Such a triplet is expected once every 13.7 years as a random coincidence of background events.
• However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%.
• Follow-up observatories were notified in order to search for an electromagnetic counterpart.