Supernova Warning System Will Give Astronomers Earlier Notice Duke University -- A Supernova Early Warning System (SNEWS) that detects ghostlike neutrino particles that are the earliest emanations from the immense, explosive death throes of large stars will alert astronomers of the blasts before they can see the flash.     SNEWS "could allow astronomers a chance to make unprecedented observations of the very early turn-on of the supernova," wrote the authors of an article about the new system in the September issue of the "New Journal of Physics."     They also noted that "no supernova has ever been observed soon after its birth."     Big stars end their lives in explosive gravitational collapses so complete that even the brilliant flashes of light usually announcing these extremely rare "supernova" events stay trapped inside, unseen by astronomers, for the first hours or days...