Scorpius X-1


Scorpius X-1

The first cosmic X-ray source, discovered during a sounding rocket experiment from White Sands, New Mexico, in June 1962. By an order of magnitude Sco X-1 is the brightest of all non-transient cosmic X-ray sources. Optically identified in 1967 with the 13th magnitude variable star V818 Sco, it was confirmed as a low-mass X-ray binary system with an orbital period of 0.78 days. The distance of Sco X-1 remains uncertain, probably lying in the range 300–600 parsecs.