Black Hole at the Center of the Milky Way Has Been Blowing a 'Wind' Since 20,000 Years Ago — Closing In on a 50-Year-Old Mystery

Explanation

At the center of our Milky Way galaxy lies a 'supermassive black hole' with a mass about 4 million times that of the Sun, known as 'Sagittarius A* (Sgr A*).' A black hole is an object with gravity so strong that not even light can escape, but gas moves violently around it.

The latest observations have found evidence that Sgr A* has been continuously blowing a 'wind (outflow)' of gas outward into its surroundings for at least the past 20,000 years. Black holes are often imagined as objects that suck in everything, but in fact they can also spew back out some of the matter and energy they fail to fully swallow.

This 'wind' is thought to suppress the formation of new stars near the galactic center and alter the distribution of gas, thereby influencing the evolution of the entire galaxy. The finding that black holes interact with galaxies not only by 'sucking in' but also by 'blowing out' material is a step forward in resolving a mystery that has been debated for about 50 years.