binary star system. artwork of the two stars of a binary star system seen from an alien planet. a giant blue star (upper left) is accompanied by a neutron star (centre right). the blue star burns brightly as a massive, short-lived star that may use up its nuclear fuel in a few million years. it has a strong stellar wind of material being lost to space. the wind has formed a shock wave around the small, super-dense neutron star that will capture the material in this process which is called bow-shock accretion. a neutron star is the remnant of a massive star that collapsed under its own gravity after its sustaining nuclear reactions ceased. around half of all stars form binaries.