Scorpius X-1
From Biocrawler, the free encyclopedia.
Scorpius X-1 is an X-ray source some 9,000 light years away. Apart from the Sun, it is the most powerful X-ray source in Earth's skies. It was discovered in 1962 by a team under Riccardo Giacconi at American Science and Engineering, Cambridge, Massachusetts, who launched an X-ray detector on an Aerobee sounding rocket to look for X-ray emissions from Earth's moon. Instead, Scorpius X-1 became the first X-ray source discovered outside the Solar System. The object was later matched with a faint blue variable star (V818 Scorpii).
Scorpius X-1 shows regular variations of up to 1 magnitude in its intensity, with a period of around 18.9 hours. This is due to a companion star that regularly eclipses Scorpius X-1 from the point of view of Earth. Scorpius X-1 itself is a neutron star whose intense gravity draws material off this companion. As this stellar material accelarates in Scorpius X-1's gravitational field, X-rays are emitted.
