The Astrophysics Podcast

What do black holes like to eat? Sometimes a steady diet of interstellar gas just isn't enough and a black hole needs to snack on a whole star. No judgment, we all get that way sometimes. But it can lead to some extremely energetic outflows, visible from across the universe. Dr. Brenna Mockler tells us all about these events, called "Tidal Disruption Events", and what we can learn from observing them.

Our universe isn't just a static, unchanging backdrop. It is constantly changing in time and we now have the technology to image it over and over again to explore all those changes. This is called Time Domain Astronomy, and Danny Milisavljevic is an expert in this field. He spends a lot of his time on the forensic science of exploding stars, to gain clues about the underlying processes that caused the explosion in the first place.

What would our solar system be like if we had two suns? Actually, this situation could be more common than you might think, as most stars are in binary systems. If a star is in a binary pair, how does that affect its life and death? Dr. Katelyn Breivik of Carnegie Mellon University tells us all about these systems and what scientists and other curious minds can learn from them.

What's the biggest thing in the universe, besides the universe itself? Well, stars live in galaxies, and galaxies live in large collections called galaxy clusters. Astronomers can study these titanic clusters of galaxies to learn about how they grow and merge with each other to assemble the universe we live in today. Dr. Kyoung-Soo Lee takes us on a journey to the largest scales in the cosmos.

For centuries, all that we have known about planets was confined to our own solar system, and its occasionally-changing number of planets (eight as of now). But in the past several decades, astronomers have developed increasingly sophisticated techniques for detecting planets outside our solar system, orbiting distant stars many light-years away. Dr. Jason Wang is an innovator who has developed powerful data analysis methods which have allowed us to take direct images of these exoplanets.

Planets orbit stars, and moons orbit planets, so what orbits a supermassive black hole? Possibly a whole lot of stuff, including a gaseous disk, thousands of stars and more "normal size" black holes! Dr. Rosalba Perna tells us about all the crazy things that could be orbiting around the supermassive black holes that we detect at the center of active galaxies.

When a star explodes, it's not finished having an impact on its surroundings. For the next thousand years or so, we can still see it as a supernova remnant, when the explosion has expanded to large enough scales that we can actually resolve an image of the explosion with modern telescopes like JWST, and it's even possible to do a forensic analysis to learn more about the cause of death. We will be talking about supernova remnants with Dr. Soham Mandal, who just recently earned his PhD from Purdue University.

What is turbulence? You've probably experienced it before on a plane (or perhaps on a river) but you might not know precisely what it is. But turbulence is all around us, and in particular we find it on some of the largest scales in the universe. Professor Yuan Li talks about turbulence and also a little unrelated bit about Mira, an unusual star with a tail!

Astronomers deal with huge datasets, and they are about to get even bigger with the construction of the Vera Rubin Observatory. When you can detect a million supernovae per year, how do we make sense of this data and decide which ones are the "most interesting" to study? Professor Ashley Villar at the Center for Astrophysics | Harvard & Smithsonian has made her career out of developing machine learning techniques to answer this very question.

What are neutrinos and where do they come from? How do we know what's going on in the interior of a star when we can only see the surface? How does a paper get accepted into a scientific journal? We discuss these questions and more with Frank Timmes, professor at Arizona State University and Associate Editor-in-Chief of a number of scientific journals run by the American Astronomical Society.