Скачать или смотреть Black hole Cygnus X-1

Cygnus X-1 (abbreviated Cyg X-1)[12] is a well-known galactic X-ray source[13] in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 2.3×10−23 Wm−2Hz−1 (2.3×103 Jansky).[14][15] Cygnus X-1 was the first X-ray source widely accepted to be a black hole candidate and it remains among the most studied astronomical objects in its class. It is now estimated to have a mass about 8.7 times the mass of the Sun[7] and has been shown to be too compact to be any known kind of normal star or other likely object besides a black hole. If so, the radius of its event horizon is probably about 26 km