Passage: Cygnus X-1 (yakapfupikiswa Cygnus X-1) is a galactic X-ray source in the constellation Cygnus, and the first such source widely accepted to be a black hole. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from the Earth, producing a peak X-ray flux density of 2.3×10−23 Wm−2 Hz−1 (2.3×103 Jansky). It remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any kind of normal star, or likely other object besides a black hole. Kana zvakadaro, iyo radius of its horizon has 300 degrees upper bound to the line of occasional X-rays of the stellar jets around the star.
Cygnus X-1