The Quest for SS433

SS 433 is one of the most exotic star systems observed. It is an eclipsing X-ray binary system, with the primary most likely a black hole, or possibly a neutron star. The spectrum of the secondary companion star suggests that it is a late A-type star. SS 433 is a microquasar, the first discovered. SS 433's designation comes from its catalogers, Case Western Reserve astronomers Nicholas Sanduleak and C. Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines. This book recounts the discovery of this unusual star, which at first seemed to be traveling both towards and away from the Earth, and describes the efforts of astronomers to explain its structure and strange behavior.