Galactic centre. Coloured composite Chandra X-ray telescope image of the centre of our galaxy, the Milky Way. The image is colour-coded to show the energy of radiation: red is low energy, green is medium and blue is high. This image is 400 by 900 light years and Galactic centre lies around 25,000 light years from Earth. It contains a supermassive black hole (in bright white region, centre), as well as other X-ray sources such as white dwarf and neutron stars (coloured dots). The X-ray data reveals high temperature gases (around 10 million degrees Celsius) escaping into the rest of the galaxy, carrying elements released by star death.