A rendering of the star S0-2 orbiting Sagittarius A*, the supermassive black hole at the heart of the Milky Way. Gas pulled away by the black hole as S0-2 made a close flyby last year could be powering recent outbursts. Image: Nicolle Fuller/National Science Foundation
The supermassive black hole lurking at the center of the Milky Way is normally fairly calm as it shapes the orbits of nearby stars. But on 13 May, the area just outside the black hole’s event horizon, the point of no return for gas and dust falling into the hole’s gravity well, suddenly flared with unprecedented intensity. It was the third such outburst this year.
While black holes are, by definition, invisible, gas and dust sucked in by their enormous gravity are accelerated to extreme velocities, generating enormous heat that produces visible high-energy radiation before the material moves past the hole’s event horizon.
“We have never seen anything like this in the 24 years we have studied the supermassive black hole,” said Andrea Ghez, UCLA professor of physics and astronomy and a co-senior author of a paper describing the observations in Astrophysical Journal Letters. “It’s usually a pretty quiet, wimpy black hole on a diet. ...