Astronomers have now brought the Event Horizon Telescope online, and turned it towards the supermassive black hole situated at the center of our Milky Way called Sagittarius A* (Sgr A*). The 10-day project will run from April 5-14, at the end of which scientists are hoping to capture real images of the environment surrounding a black hole, including its event horizon.
The eight radio telescopes taking part in the project are located in different countries around the world, and have linked up to form a powerful network capable of producing detailed images in very small parts of the sky. These include the ALMA in Chile, the CSO in Hawaii, the LMT in Mexico, the SPT in Antarctica, as well as other facilities located in Spain and France. While the data will be collected over a 7-and-a-half day period, the Event Horizon Telescope will continue gathering information for a few more days, after which it may take months before we finally see the first images of the region surrounding Sagittarius A*.
Our Milky Way‘s black hole lies a relatively close 25,600 light-years from Earth in the constellation of Sagittarius, and is an estimated 0.39 to 100 AU in size, with 1 AU representing 93 million miles (150m kms) or the distance between the Sun and Earth. It also weighs around 4 million solar masses, and is situated at the center of our galaxy, qualifying it as a supermassive black hole, compared to stellar black holes which are gravitationally collapsed massive stars that are scattered across the universe, and typically weigh between 5 to 10 solar masses.
Studying the immediate environment around Sagittarius A* will help scientists to test Einstein’s theories and gravitation equations, and as it explains on the Event Horizon Telescope site: “Realizing this goal would open a new window on the study of general relativity in the strong field regime, accretion and outflow processes at the edge of a black hole, the existence of an event horizon, and fundamental black hole physics.”