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Cygnus X-1 (abbreviated Cyg X-1) [11] is a galactic X-ray source in the constellation Cygnus and was the first such source widely accepted to be a black hole. [12] [13] It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources detectable from Earth, producing a peak X-ray flux density of 2.3 × 10 −23 W/(m 2 ⋅Hz) (2.3 × 10 3 jansky).
Betty Louise Turtle (née Webster [also Webster in published works]) (20 May 1941 - 29 September 1990) was an Australian astronomer and physicist.In 1971, with her colleague Paul Murdin, she identified the powerful X-ray source Cygnus X-1 as the first clear candidate for a black hole.
Cygnus X-1 belongs to a massive X-ray binary system; this system, about 6,000 light-years away, includes a blue variable supergiant cataloged as HDE 226868, whose orbit is about 0.2 AU. A strong stellar wind from this star transfers large amounts of matter to an accretion disk surrounding its companion, the X-ray source. [9]
They measured the Doppler shift to find that HDE226868 was a binary star with an orbit of 5.6 days orbiting an invisible partner, presumably the source of the X-rays, and which they calculated to be certainly more than 2.5 and probably more than six solar masses. Such a star cannot be a white dwarf or neutron star and they assumed this body to ...
The DDO is the site of a number of important scientific studies, including pioneering measurements of the distance to globular clusters, providing the first direct evidence that Cygnus X-1 was a black hole, and the discovery that Polaris was stabilizing and appeared to be "falling out" of the Cepheid variable category. [1]
It was discovered after maximum light, and the photographic magnitude range was measured at 12.5–20.5. [13] On May 22, 1989 the Japanese Ginga Team discovered a new X-ray source that was catalogued as GS 2023+338. [14] This source was quickly linked to V404 Cygni, which was discovered to be in outburst again as Nova Cygni 1989. [15] [16]
Sh 2-101, at least in the field seen from Earth, is in close proximity to microquasar Cygnus X-1, site of one of the first suspected black holes. Cygnus X-1 is located about 15 ′ west of Sh 2-101. The companion star of Cygnus X-1 is a spectral class O9.7 Iab supergiant with a mass of 21 solar masses and 20 times the radius of the Sun.
"Cygnus X-1" is a two-part song series by Canadian progressive rock band Rush. The first part, "Book I: The Voyage", is the last song on the 1977 album A Farewell to Kings, and the second part, "Book II: Hemispheres", is the first song on the following album, 1978's Hemispheres. Book I is ten minutes and twenty-five seconds long (10:25), and ...