Milky Way galactic centre, illustration. At centre is Sagittarius A* (Sgr A*), the supermassive black hole that is 26,000 light years from Earth, at the centre of our galaxy. The red disk depicts hot gas that has been captured by the black hole and is being pulled inwards. The source of the hot gas is young, massive stars, shown in blue, orbiting around Sgr A*. The illustration also shows a large amount of material being thrown outwards. Image published in 2013.