Scorpius X-1

[4] The possible existence of cosmic soft X-rays was first proposed by Bruno Rossi, MIT professor and board chairman of American Science and Engineering in Cambridge, Massachusetts to Martin Annis, president of AS&E.

Following his urging, the company obtained a contract from the United States Air Force to explore the lunar surface prior to the launch of astronauts to the Moon, and incidentally to perhaps see galactic sources of X-rays.

Subsequently, Scorpius X-1 was discovered in 1962 by a team, under Riccardo Giacconi, who launched an Aerobee 150 sounding rocket carrying a highly sensitive soft X-ray detector designed by Frank Paolini.

[6][7] Historical footnote: "The instrumentation had been designed for an attempt to observe X-rays from the moon and was not equipped with collimation to restrict the field of view narrowly.

[8] In 1967 (before the discovery of pulsars), Iosif Shklovsky examined X-ray and optical observations of Scorpius X-1 and correctly concluded that the radiation comes from a neutron star accreting matter from a companion.

[4] Scorpius X-1 itself is a neutron star whose intense gravity draws material off its companion into an accretion disk, where it ultimately falls onto the surface, releasing a tremendous amount of energy.