Bob Harmon, Professor of Physics and Astronomy
Schimmel Conrades Science Center, Room 161
Our Sun is a giant thermonuclear fusion reactor, getting the energy by which it shines from the fusion of hydrogen into helium in its core. It has been doing this for about four and a half billion years now, but its supply of hydrogen fuel in its core won't last forever. When it runs out in about five billion years, the Sun will switch to furiously fusing hydrogen in a thin shell surrounding the core, which will cause the Sun to swell up and become a red giant a hundred times larger and several thousand times brighter than it is at present! And that will be just the beginning of the end for the Sun. We'll trace the further chapters in the Sun's story until it leaves behind its final remnant, a white dwarf that is its burnt-out core, a teaspoon of which would have the mass of a delivery truck. Then we'll see how more massive stars end their lives with titanic supernova explosions that leave behind neutron stars or even black holes!