... Star Atlas . ... Half of all exoplanet host stars are binaries . ... BINARY STARS | ... A team of astronomers, led by Elliott Horch of Southern Connecticut State University, has shown that stars with exoplanets are just as likely to have a binary companion that is, 40 to 50 percent of the host stars are actually binary stars. ... By noting the occurrence rate of these true binary companion stars, the discoveries can be extended to show that half of the stars that host exoplanets are probably...