Lesson Four : Supernovae
The death of a super massive star having 8 to 15 times the mass of our Sun is more exciting. At the end of its main sequence lifetime, when all of its constituents have been fused into iron, its core collapses in upon itself to an almost unimaginable density. The mass of the star is so great that its gravitational forces fuse the protons and electrons into neutrons.Eventually, all the atoms making up the star are turned into neutrons. At this stage, further collapse is not possible, and as the outer layers of the star contract toward the center, they suddenly bounce off of the dense core in a cataclysmic explosion called a supernova.
VLBI image of SN 1987a
NRAO / AUI
NRAO / AUI
Supernovae are some of the most interesting and informative cosmic objects to observe in any spectrum. For a short time, the light from this explosion outshines all the combined stars in its host galaxy. Some historical supernovae in our own galaxy were even visible in the daytime.