The SuperNova Early Warning System: Brief Description

When a massive star collapses at the end of its life, most of its binding energy is emitted in the form of neutrinos. These neutrinos come in all flavors and emerge promptly from the stellar envelope over a timescale of tens of seconds. If the star later explodes, the burst of supernova photons does not become visible until hours later. The observation of a neutrino burst can provide a warning for astronomers that the opportunity to get a rare glimpse at the collapse of a star, resulting in a supernova, may be soon be presenting itself. A number of neutrino experiments with sensitivity to a gravitational collapse event in our Galaxy are currently online, or will be in the future. In addition, gravitational wave detectors like LIGO and Virgo have sensivity to asymmetrically-collapsing supernovae.

The basic idea of the early supernova alert project is to have a central computer (or computers) which accepts neutrino burst candidate messages from neutrino detectors around the world and sends an alarm message to astronomers if it finds a coincidence within a short period of time (10 seconds). The central computer is located at Brookhaven National Lab. The coincidence search is both "blind" (decision is made when messages are received without polling the other experiments) and automated (alerts go out without human intervention, for maximum speed.) The neutrino experiments currently involved are Super-K, LVD, IceCube, Borexino, KamLAND, Daya Bay, and HALO.