A Black Hole at the Centre of our Galaxy

What lies at the centre of the Milky Way? For a long time, astronomers have suspected that a black hole lurks at the heart of our Galaxy, but could not be sure. Just recently, after 15 years of regular monitoring of the Galactic Centre with ESO telescopes at the La Silla Paranal Observatory, scientists finally obtained conclusive evidence.

"We needed even sharper images to settle the issue of whether any configuration other than a black hole is possible and we counted on the ESO VLT to provide those. Now the era of observational black hole physics has truly begun!"

Reinhard Genzel, Director at the Max-Planck Institute for Extraterrestrial Physics

ESO Observations

Stars at the centre of the Milky Way are so densely packed that special imaging techniques such as Adaptive Optics were needed to boost the resolution of the VLT. Astronomers were able to watch individual stars with unprecedented accuracy as they moved around the Galactic Centre. Their paths conclusively showed that they must be orbiting in the immense gravitational grip of a supermassive black hole, almost three million times more massive than our Sun.The VLT observations also revealed flashes of infrared light emerging from the region at regular intervals. Whilst the exact cause of this phenomenon remains unknown, observers have suggested the black hole may be spinning rapidly. Whatever is happening, the black hole’s life is not all peace and quiet. See ESO Press Release 17/02 and Press Release 26/03

Astronomers also use the VLT to peer into the centres of galaxies beyond our own, where they again find clear signs of supermassive black holes. In the active galaxy NGC 1097, they could see with unprecedented detail a complex network of filaments spiralling down to the centre of the galaxy and possibly providing for the first time a detailed view of the channelling process of matter, from the main part of the galaxy down to its very end in the nucleus. See ESO Press Release 04/01, Press Release 17/03, Press Release 10/04, Press Release 23/05, and Press Photo 33/05

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