When massive stars die, they do so in a spectacular fashion. Supernovæ come in two different varieties called, quite logically, type I and type II. Type I supernovæ are thought to be white dwarfs which are pushed over the edge of the Chandrasekhar limit , which is named in honor of Subrahyanman Chandrasekhar, who first used physics to calculate the value. The enlarged white dwarf would then become unstable and detonate . These are known as carbon detonation supernovæ. Type II supernovæ are massive red supergiant stars which have quickly evolved to the stage where many layers of nuclear fusion are found in the interior of the star. When the evolved star reaches iron fusion, the core collapses. On the rebound, we have a huge release of neutrinos and quite a bit of visible light as well. Most recently, astronomers were treated to a relatively nearby supernova in the Large Magellanic Cloud . Here’s a NOVA documentary that was made soon after the discovery with all of the details of that discovery. Supernova 1987a has been fading since, and has left behind some interesting features, such as light rings . Other supernova remnants may be found throughout the sky. The last nearby supernova was over four hundred years ago . Fortunately, it seems that each of the two types of supernovæ explodes in the same way and each type has a distinctive light curve . Why is that fortunate for us? Recall that if there is a way to know the absolute magnitude of an object, one can measure the apparent magnitude and calculate the distance! Very handy for establishing the distances to other galaxies. Let’s see what this might mean to what we might observe in the sky. The Red Giant Betelguese might go supernova soon. This star is 643 light years away. What would we see? Let’s calculate ! Any star’s life ultimately ends as one of three possible outcomes: white dwarf, neutron star, or black hole.