Stars: Attributes, Energetics, End Stages

Abstract

“Twinkle, twinkle, little star/How I wonder what you are....” For some, these lines could evoke childhood memories, but to those with an interest in astronomy, they may suggest a truth, a miniaturization, and a major scientific achievement. Stars do “twinkle,” but only because they are observed through the earth’s turbulent atmosphere. Like the random movements of particles suspended in liquids, the twinkling is a result of the motion of atoms and molecules. This turbulence affects the seeing from earth-based optical telescopes, but through the use of “adaptive” optics, telescope mirrors can be made flexible enough to partially compensate for the atmospheric distortion. “Little stars” appear to be miniaturized, but only because of their enormous distance from the earth: apart from white dwarfs, neutron stars, and nonmassive black holes, stars are huge. An example is the sun, whose mass and volume, respectively, are roughly 300,000 and a million times that of the earth.