Microquasars
Every generation of astronomers is dealt a new mystery to solve. In the late 1970s, the mystery was the discovery of a ‘star’ with very unusual properties, leading astronomers to suspect they were on to a new class of phenomena. This object, SS 433, was the 433rd listed in a 1977 catalogue of Milky Way H-alpha emission stars compiled by C. Bruce Stephenson and Nicholas Sanduleak, astronomers at Case Western Reserve University. Subsequent observations showed that its optical spectrum exhibited peculiar emission lines; it also turned out to be a variable source at radio and X-ray wavelengths. But what clinched the mystery was the discovery of an elongated feature in the radio data. This combination of properties couldn’t be reconciled to any single known model. At the time, no
