Skip to content

Astronomers capture first image of black hole at center of Milky Way

Astronomers have captured the first image of the black hole at the center of the Milky Way.

Why it matters: The “historic breakthrough” offers an unprecedented look at the extreme object driving the evolution of our galaxy and could yield new clues about the physics governing the universe.

Driving the news: Astronomers imaged Sagitarrius A* (Sgr A*) — the black hole at the center of the Milky Way — using the Event Horizon Telescope (EHT), scientists announced at a press conference Thursday.

Most galaxies are thought to have a supermassive black hole at their center.Sgr A* is less than 26,000 light years from Earth — far closer than the supermassive black hole at the center of galaxy Messier 87, the first imaged by EHT. At about 4 million times the mass of the Sun, it is also far smaller than the 6.5 billion solar masses of M87* suggested by the EHT measurements. As a result, Sgr A* changes much faster — on the order of minutes rather than weeks — and needs to be imaged quickly.Light can’t escape a black hole but hot plasma swirling around it emits short radio waves that radio telescopes can pick up. In the image, that gas silhouettes the black hole itself.

What they’re saying: “For decades, astronomers have wondered what lies at the heart of our galaxy, pulling stars into tight orbits through its immense gravity,” Michael Johnson, an astrophysicist at the Center for Astrophysics, said in a press release.

“With the EHT image, we have zoomed in a thousand times closer than these orbits, where the gravity grows a million times stronger. At this close range, the black hole accelerates matter to close to the speed of light and bends the paths of photons in the warped spacetime,” Johnson added.

The very big picture: Black holes can tear apart and devour nearby stars, generate massive bursts of gamma-ray energy that shape the galaxies around them and, recent evidence suggests, ignite the formation of new stars.

Einstein’s theory of general relativity predicts the existence of black holes — and his century-old rule consistently passes cosmic tests near and far.But scientists hope these massive, dense objects may also reveal instances where general relativity doesn’t hold. These important limits could point them to conditions that require a new physics to describe. Any new physical laws, together with general relativity and Newtonian physics, could give us a more complete view of the physics of the universe.

This is a developing story. Please check back for updates.