A group of scientists on Tuesday unveiled the first-ever photograph of a black hole.
The Event Horizon Telescope, a collaboration between more than 200 scientists using telescopes from around the world, shot photographs of a supermassive black hole in the galaxy M87.
Black holes are regions in space where gravity is so strong that not even light can escape — and they’re notoriously camera-shy. Humans have never managed to capture a photograph of one before. To attempt this shot, the telescopes involved in the project found the black hole’s shadow on a brighter point in the sky.
Brad Benson is part of the South Pole Telescope, which one of the teams involved. He’s also a professor of Astronomy and Astrophysics at the University of Chicago, and he joins the Morning Shift to explain the mission’s initial results.
What does a black hole look like?
Brad Benson: If you know anything about black holes, [you know they’re] so dense, their gravity is so strong, that not even light can escape its gravitational pull, and that region is called the event horizon. And so what we can see in the image is actually that shadow, the event horizon of this black hole, and then a ring of light around it, which is the light from behind the black hole actually getting bent by gravity and distorted, creating this ring-like structure.
How black holes form
Benson: In some ways, it is a little bit of a mystery how these supermassive black holes form. I mean, for massive stars at the end of their lifetime, they eventually explode in this thing called a supernova, and the centers of those stars often collapse and form black holes. They’re on the order of several times the mass of our sun….Supermassive black holes are things that form much earlier in the universe’s history, billions of years ago, and basically over time just accrete matter, and accrete stars. As the universe evolves, gravity basically pulls in things around these supermassive black holes, and basically creates the seeds for forming galaxies.
What the photo tells us
Benson: Well, I think most importantly, it’s really the first direct visual evidence that black holes exist. We’ve had a lot of indirect evidence that they exist, by the orbits of stars, by looking at this bright x-ray emission that’s coming from the center of the black hole, but for the first time we’re actually getting this image where you actually see the black part of the black hole, which we’ve never seen before….It’s testing gravity in a way that we really can’t test any place else in the universe, this place where the gravity is the strongest possible.
Coordinating several telescopes to focus on the same point
Benson: It requires pretty tight coordination. So there are telescopes in Arizona, Hawaii, Spain, Chile, and Antarctica at the South Pole where we are, basically all coordinating, doing the same observations of the same objects at the same time. So it requires that the weather is good at all these places, [and] it requires that you have very precise timing of making sure these instruments are actually aligned with one another.
GUEST: Brad Benson, professor of Astronomy and Astrophysics, University of Chicago
LEARN MORE: The Event Horizon Telescope Is Trying to Take the First-Ever Photo of a Black Hole (Space.com 4/8/19)
National Science Foundation press conference on the initial findings