Abstract
Degenerate bodies composed primarily of dense hydrogen and helium plasmas range from giant planets to the so far hypothetical brown dwarfs. More massive objects begin their lives as nondegenerate stars and may end as white dwarfs, composed primarily of carbon and oxygen, or as neutron stars, with solid crusts of iron or heavier elements and cores of neutron matter. The physical properties of dense plasmas that are necessary to construct theoretical models of such degenerate stars include the equation of state, transport properties, and nuclear reaction rates.