For 10 points, name these systems in which two of the namesake objects rotate each other, examples of which include Algol, Sirius, and Alpha Centauri.
F. G. Pease credited Henry Russell with contributing to the first analysis of these objects using the "20 foot interferometer," though Russell is not listed as a co-author. Independently controlled apertures were first used to study these objects by Hanbury et al via the Narrabri Stellar Intensity Interferometer. The satellite Uhuru discovered high-luminosity (*) x-ray sources located in these objects; they are almost all x-ray pulsars and the best known of them is an object in Cygnus yielding evidence that black holes may exist in them. Coming in astrometric, eclipsing and spectroscopic varieties, they were first discovered by William Herschel. A theory that the Sun is part of one of them postulates the existence of a star called Nemesis. For 10 points, name these systems in which two of the namesake objects rotate each other, examples of which include Algol, Sirius, and Alpha Centauri.
F. G. Pease credited Henry Russell with contributing to the first analysis of these objects using the "20 foot interferometer," though Russell is not listed as a co-author.
{binary} star systems [accept {binary star}s; accept {double star}s]