The IceCube Collaboration is operating the world’s most sensitive high-energy neutrino detector. Deployed between 1.5 and 2.5 km depth in the Antarctic glacier ice at the South Pole, the detector is taking data with an uptime of >99%, monitoring the full neutrino sky with peak sensitivity in the northern hemisphere.
Neutrino events are reconstructed in real time, and based on energy and topology classified as of atmospheric or of astrophysical origin. Events with the highest score (purity at least 30%) for being astrophysical origin are sent out as public GCN alerts (about 20 per year) for electromagnetic follow-up.
Link: https://icecube.wisc.edu