Space and Science

The Milky Way’s supermassive black hole is feasting

CNN  — 

Earlier this year, astronomers were surprised to spot “unprecedented” changes in the supermassive black hole at the center of our galaxy. Now, they may have a better understanding of what they witnessed: the black hole enjoying an interstellar feast of gas and dust.

Astronomers were using the European Southern Observatory’s Very Large Telescope in Chile and the W.M. Keck Observatory in Hawaii to observe the supermassive black hole at the center of the Milky Way in April and May.

It’s 26,000 light-years from Earth, but it’s the closest black hole we can see, even if it’s largely obscured by dust.

This black hole, known as Sgr A*, has shown variability before. It’s been observed for years in multiple wavelengths of light. But on three of the evenings they observed it, it was unusually bright.

The unusually bright flux levels and variability showed peaks that exceeded twice the historical measurements of the black hole. What the astronomers were seeing was an eruption of the black hole unleashing bright radiation.

In addition to these bright levels, on two nights in May they also saw large drops in brightness occur over the course of minutes.

Some of the astronomers involved in the study, including Tuan Do at the University of California, Los Angeles who initially drew attention to the outburst by tweeting about it, have been observing the black hole for years. They’ve analyzed 13,000 observations from 133 nights since 2003.