Sagittarius A* - a giant black hole in the middle of the Milky Way

On Thursday scientists provided the first look at a black hole located in the centre of the Milky Way galaxy. The images show a supermassive stellar mass that consumes any matter within its gravitational pull, Reuters reported.

The black hole, called Sagittarius A*, or SgrA*, is only the second in history to be imaged. The feat was provided by the Event Horizon Telescope (EHT) international collaboration. In 2019 the collaboration unveiled the first-ever photo of a black hole residing at the heart of a different galaxy.

“Observations of stars orbiting around it revealed the presence of an object that is very massive, 4 million times the mass of our sun, but also very faint … until now, we didn't have the direct picture confirming that Sgr A* was indeed a black hole,” Feryal Özel, Professor of Astronomy and Physics at the University of Arizona said.

“Because the black hole is about 27,000 light-years (9.5 trillion km) away from Earth, it appears to us to have about the same size in the sky as a donut on the Moon. To image it, the team created the powerful EHT, which linked together eight existing radio observatories across the planet to form a single “Earth-sized” virtual telescope [1]. The EHT observed Sgr A* on multiple nights, collecting data for many hours in a row, similar to using a long exposure time on a camera,” EHT News Blog wrote.

We finally have the first look at our Milky Way black hole, Sagittarius A*. It’s the dawn of a new era of black hole physics. Credit: EHT Collaboration. #OurBlackHole #SgrABlackHole
Link: https://t.co/Ax7ECRVg8A pic.twitter.com/LRWizSYOy9

— Event Horizon 'Scope (@ehtelescope) May 12, 2022

Black holes, galaxys and the Event Horizon Telescope

Black holes are extraordinarily dense objects with gravity so strong that not even light can escape. A black hole’s event horizon is the point of no return beyond which anything - stars, planets, gas, dust and all forms of electromagnetic radiation - gets dragged into oblivion.

The Milky Way is a spiral galaxy that contains at least 100 billion stars. Viewed from above or below it resembles a spinning pinwheel, with our sun situated on one of the spiral arms and Sagittarius A* located at the centre.

The Event Horizon Telescope is a global network of observatories working collectively to observe radio sources associated with black holes. The project was launched in 2012 to try to directly observe the immediate environment of a black hole.

Thursday’s announcement was made in simultaneous news conferences in Chile, China, Germany, Japan, Mexico, the US and Taiwan.