Guest blog: Bucket List Astronomy Class, day 5

Posted by Nicole Kiefert
on Thursday, August 03, 2017

Dr. Richard McDermid uses a still from the movie 'Interstellar: to help us understand the weird world of black holes. // Photo by Samuel I. Beard, Jr.
Supermassive Black Holes, Lasers, and Adaptive Optics….OH MY!

By Maya Fitch and Sarah Deitrich

On Day 6, we went to Macquarie University to hear a presentation by Dr. Richard McDermid, a lecturer and researcher at Macquarie University. Just the title sounded exciting: “Lighting the Dark – Weighing Supermassive Black Holes with Lasers.”

What's a black hole? It's an object so compact that not even light can escape. Dr. McDermid told us that a "normal" black hole comes from stars, but not just any stars. They come from red supergiants that go supernova. If the leftover mass is great enough, it creates a black hole. But that's not the kind of black hole he studies. Something hiding in the heart of a galaxy is a supermassive black hole with millions or even billions of times the mass of a single star.  But like their smaller cousins, they do not allow any light to escape.

Our minds blown, we pose for a photo with Dr. McDermid. // Photo by Samuel I. Beard, Jr.
So how do you weigh a thing you can't see? First you look at what it's doing to the things around it. In the case of the Galactic center, there are stars that appear to be orbiting NOTHING! But that 'nothing' turns out to be a black hole with 4 million times the mass of the Sun, and those orbiting stars are just following the same rules that we've been learning about in class. 

Looking into the center of the Milky Way is tricky. There's lots of dust in the way, and if that weren't bad enough, Earth's atmosphere causes everything to twinkle. Observatories, with the help of adaptive optics, are able to get rid the 'twinkling' effect our atmosphere causes on stars. Basically the distortion of the light is canceled out by constantly changing the shape of the mirror. To figure out exactly what the atmosphere is doing, astronomers fire lasers into the sky, exciting sodium in the upper layers and creating "fake" stars that tell them how things are shimmering. Once the twinkling effect is removed, we are able to better gather information of the stars. 

The whole talk was mindboggling. It's amazing to see the lengths astronomers go to to understand our universe. and we would like to sincerely thank Dr. McDermid for sharing his time and knowledge.

Dr. McDermid zooms in to the center of our Milky Way Galaxy to find a whole lot of stars orbiting...nothing! Or that's how it appears. It turns out there's a supermassive black hole behind the scenes. // Photo by Samuel I. Beard, Jr.
ABOUT THE AUTHORS:

My name is Sarah Deitrich and I am a mass communication major with an emphasis on film. I'm currently a junior at SHSU. Obviously my major has nothing to do with this subject, but I absolutely love learning about space. I was going to take this class last fall but once I got word about this trip, I knew I had to seize the opportunity while it was there.

I’m Maya Fitch, and I am a sophomore philosophy major at SHSU. I was hesitant about coming on this trip because I've never been this far before, but I'm glad I changed my mind. So far this trip has been one to remember and I can't wait to learn more things!

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