Scorpius X-1
16h 19m 55.07s, −15° 38′ 24.8″| Observation data J2000.0
| |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 19m 55.07s[1] |
| Declination | −15° 38' 24.8"[1] |
| Apparent magnitude (V) | 12.2[1] |
| ) | |
| 1617-15 | |
| Database references | |
| SIMBAD | data |
Scorpius X-1 is an
Discovery and early study
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. The rocket trajectory was slightly off course but still detected a significant emission of soft X-rays that were not coming from the Moon. Thus fortuitously, and as first pointed out by Frank Paolini, Scorpius X-1 became the first X-ray source discovered outside the Solar System. The angular resolution of the detector did not initially allow the position of Scorpius X-1 to be accurately determined. This led to suggestions that the source might be located near the Galactic Center, but it was eventually realized that it lies in the constellation Scorpius.[4] As the first discovered X-ray source in Scorpius, it received the designation Scorpius X-1.
The
Although the above reference indicates the rocket launch was on June 12, 1962, other sources indicate the actual launch was at 06:59:00 UTC on June 19, 1962.[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. As a result, the signal was very broad, and accurate definition of the size and position of the source was not possible. A similar experiment was repeated in October 1962 when the Galactic Center was below the horizon and the strong source was not present. A third attempt, in June 1963, verified the results of the June 1962 flight."[8] The Galactic Center is < 20° RA and < 20° Dec from Sco X-1, the two X-ray sources are separated by ~20° of arc and may not have been resolvable in the June 1962 flight.[8]
Scorpius XR-1 has been observed at J1950 RA 16h 15m Dec −15.2°.[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.[9]
Characteristics
Its X-ray output is 2.3×1031
This system is classified as a
See also
References
- ^ a b c Staff (March 3, 2003). "V* V1357 Cyg—High Mass X-ray Binary". Centre de Données astronomiques de Strasbourg. Retrieved 2009-12-21.
- ^ doi:10.1086/311889.
- .
- ^ ISBN 978-0-7167-0024-1.
- .
- ^ Drake SA (September 2006). "A Brief History of High-Energy Astronomy: 1960–1964".
- ^ "Chronology—Quarter 2 1962". Archived from the original on 2010-01-18.
- ^ Bibcode:1965IAUS...23..227B.
- doi:10.1086/180001.
- .
- S2CID 14136652.
- S2CID 2585509.
