Missinig Neutrinos and Energy, from the SuperNova of 1987A.

The nearest Supernova to the Earth, in modern times, was the Supernova in the Magellaniic Cloud, 1987a, some 168,000 Light Years Aways from us. A few (25) of the neutrinos emitted by the 1987A, where actually measured on Earth, confirming the theory, that it is the neutrinos from the collapse of the inner core of a super nova to become a neutron star, that blow off the outer layers of the star, resulting in the observed supernova. Recently, Shirley Weishi Li et Al, have reanalysised the neutrino data from 1987, and found a deficit in both neutrino counts and neutrino energies, with the observed data, having significantly less number count and energy than the theorectical models of supernova explosions. The star that became the explosion 1987A was the Blue Supergiant Sanduleak 69-202, with a mass of 20 Solar Masses, via a Type II - Core Collapse Supernova, although there are competing theories of it being a binary pair of stars that merged (Supernova Type IA).