|Cygnus X-1 Copyright David A. Hardy|
One of the first suspected examples of a black hole was Cygnus X-1. In 1972 a massive blue supergiant star in Cygnus was found to have an invisible companion which emitted X-rays. This was calculated to be 14 times as massive as the Sun – too massive to be a neutron star, so a black hole is the most likely explanation. Here it is seen pulling material away from its companion and becoming strongly heated; hence the X-rays. Excess gas is ejected in two very active jets above and below the disc. (Digital, from Futures.)
Today on Discovery Enterprise we take a breathtaking journey into the future, five billion years from now, to see the ultimate fate of the Solar System and other violent and destructive events which shape our Universe.
This gem from Hubble Cast showcases stunning Hubble imagery of the death throes of Sun-like stars. The wreckage of these dying stars form the building blocks of new generations of stars.
|Jetting Galaxy Copyright David A. Hardy|
We cannot see the centre of our own galaxy, but it is believed that the nucleus contains a massive black hole, known as Sagittarius A-* (A-star). Indeed most galaxies probably have a black hole at their heart, sweeping up interstellar material into an accretion disc, which persists for some time before the hot gases finally plunge over the 'event horizon' into the black hole. Radiation from the hole is guided into narrow jets above and below the 'doughnut' of matter, as here. (Digital, from Futures.)
The Galactic Centre harbours the closest supermassive black hole known, and the one that is also the largest in terms of its angular diameter on the sky, making it the best choice for a detailed study of black holes.
Today, energy is very much on our minds, as we search for ways to power our civilization and serve the needs of our citizens. But what is energy? Where does it come from? And where do we stand within the great power streams that shape time and space?
EsoCast showcases a new Hubble image of a giant cloud of hydrogen gas illuminated by a bright young star. The image shows how violent the end stages of the star formation process can be, with the young object shaking up its stellar nursery.
In the plane of our galaxy, GRS 1915 is a star with a black hole bound together by gravity. This 14 solar mass black hole is steadily drawing mass from its companion.