X-raying Black Holes
Channel: Dr. Abbie Stevens
Date: 2021-09-08

My 90-second submission to the Skype A Scientist No Time Like The Presentation competition!

More about me: https://abigailstevens.com/

Transcript: 
Hi I'm Dr. Abbie Stevens, I'm an astronomer in Michigan, and I research black holes! I focus on stellar black holes, which are formed in the supernova of a really big star at the end of it's life. Black holes get their name because their gravity is so strong that not even light, which is the fastest thing in the universe, can escape. So they look black to us. But even though light can't escape from inside them, we know where lots of them are and we can study black holes and the effects they have on the space environment around them. I do this by looking at black holes that are orbiting around with a star friend, kind of like how the earth and moon are gravitationally bound and orbit around each other.  The star and the black hole are close enough together that the stuff on the very outer part of the star is more gravitationally attracted to the black hole than to its own star. So the black hole is slowly draining its friend of its star-stuff because it's a bad friend. As the gas from the star falls towards the black hole, it swirls around and forms a disk around the outside of the black hole. We call this an accretion disk. This disk gets super hot and shines really bright heat-light in the X-rays. For comparison, the human body is hot and shines heat-light in the infrared, the Sun shines in heat-light in the visible since its hotter than a human body, and accretion disks are even hotter than the sun, so they shine heat light in the X-ray. I use X-ray telescopes to observe the X-ray light coming from the accretion disk to learn about the black hole in the middle. We do this because these stellar black holes are too small and too far away to just take a picture to see what's happening around them. Thanks, see you later!