Contrary to what its name suggests, the black hole at the center of our Milky Way galaxy is not an empty void. It’s a piece of space that weighs as much as several million suns. Here, gravity reigns, and it is relentless; the black hole tugs inexorably at anything that gets too close—a cloud of cosmic dust, an entire star the size of our sun—and swallows it. Nothing, not even light, can escape a black hole’s maw, which means astronomers on Earth, watching the meal from afar, can’t see it.
Astronomers know that the black hole is there because they can observe what’s happening around it. With telescopes, they have captured the chaotic conditions around a seemingly empty spot in space. Stars whip around at extraordinary speeds. Gas and dust accumulate into a rotating disk that glows brightly as it moves. Streams of powerful radiation and energetic particles erupt from this disk and surge into space.
This pinwheel of cosmic matter at the heart of the galaxy can be difficult for us layfolk to fathom. But we don’t have to rely on our imagination.
Astronomers on Wednesday reported new telescope observations of the environment around the Milky Way’s supermassive black hole, named Sagittarius A* (pronounced “a-star”), and they transformed the data into a lively animation: