Astro Sat measured the X-ray polarisation of the Cygnus X-1 black hole system from data collected over the last eight years of operation.
Astro Sat is the India’s first, dedicated multi-wavelength astronomy mission.
Discovered over four decades ago, Cygnus X-1 is one of the first confirmed black hole systems in our galaxy.
It is located at a distance of 400 million times the distance between the Sun and Earth.
The black hole in Cygnus X-1 is 20 times heavier than the Sun, and has a companion - a heavy supergiant star (40 times more massive than the Sun) in a binary system.