Sirius (source code)
= Sirius
{c}
{wiki}
<Sirius> is a nearby <binary star> containing a luminous <main-sequence star> and a much fainter <white dwarf>. Their coexistence makes a useful lesson in stellar appearance: a hot object can be faint because its radiating <area> is small. The resolved <Hubble Space Telescope> image separates the compact companion from the bright primary's surrounding light.<The Dog Star, Sirius A, and its tiny companion by European Space Agency>[Image description: Sirius A and its small, faint white-dwarf companion]{ref}
The common <orbit> provides dynamical information, whereas <spectral classification> and <luminosity> constrain the two bodies' physical states. The <white dwarf> records prior <stellar evolution>; its current faintness does not mean it was always the less massive or less luminous member. <Sirius> therefore connects <binary star> measurements with <white-dwarf cooling> and the interpretation of the <Hertzsprung-Russell diagram>.
Back to article page
