The Black Hole Sagittarius A*

Image (Credit): The first image of Sagittarius A*, the supermassive black hole at the center of our galaxy. (EHT Collaboration)

The Event Horizon Telescope (EHT), an array linking together eight existing radio observatories across the planet, has created the first image of the supermassive black hole at the center of the Milky Way galaxy. Named Sagittarius A* after a radio signal coming from a location in the direction of the constellation of Sagittarius (the A and * came later), the black hole is 27,000 light-years away and estimated to be four million times more massive than our Sun. The presence of the black hole was not in question, but capturing an image such as this took many years of work.

A press release from the European Southern Observatory (ESO) quoted EHT Project Scientist Geoffrey Bower from the Institute of Astronomy and Astrophysics, Academia Sinica, Taipei:

We were stunned by how well the size of the ring agreed with predictions from Einstein’s Theory of General RelativityThese unprecedented observations have greatly improved our understanding of what happens at the very centre of our galaxy, and offer new insights on how these giant black holes interact with their surroundings.

For more on the recent breakthrough, you may want to view the ESO Press Conference on the new Milky Way results from the EHT team (here on Youtube), which is followed by a public question and answer event.