Stars and statistical physics: A teaching experience

The physics of stars, their workings and their evolution, is a goldmine of problems in statistical mechanics and thermodynamics. We discuss many examp les that illustrate the possibility of deepening student's knowledge of sta tistical mechanics by an introductory study of stars. The matter constituti ng the various stellar objects provides examples of equations of state for classical or quantal and relativistic or non-relativistic gases. Maximum en tropy can be used to characterize thermodynamic and gravitational equilibri um which determines the structure of stars and predicts their instability a bove a certain mass. Contraction accompanying radiation induces either heat ing or cooling, which explains the formation of stars above a minimum mass. The characteristics of the emitted light are understood from blackbody rad iation and more precisely from the Boltzmann-Lorentz kinetic equation for p hotons. The luminosity is governed by the transport of heat by photons from the center to the surface. Heat production by thermonuclear fusion is dete rmined by microscopic balance equations. The stability of the steady state of stars is controlled by the interplay of thermodynamics and gravitation. (C) 1999 American Association of Physics Teachers.