The Astrophysics Podcast

Up in Orion's shoulder sits Betelgeuse, a supergiant star near the end of its life. The surface of Betelgeuse has been roiling and pulsing for centuries, as long as humans have recorded its modulated luminosity. Dr. Jared Goldberg is a postdoctoral research fellow at the Center for Computational Astrophysics in the Flatiron Institute in New York City. Dr. Golberg has been developing computer models for Betelgeuse to help understand and interpret its oscillations over time.

What happens when a black hole eats up a star? Apparently a lot of things happen, and if you wait around awhile and look in the radio, even more things happen! Dr. Yvette Cendes tells us what it's like to be a radio astronomer and about her latest research into tidal disruption events (TDE's), when a black hole shreds up a star and eats it, producing a dramatic light show across the electromagnetic spectrum.

Some things happen out in the universe that are too powerful to make in a lab. Other phenomena are so coherent and well-ordered, we can't figure out how they can be made without a lab! Fast radio bursts are an incomprehensible combination of both; they are extremely powerful, highly coherent, and very rapid bursts of radio emission. Dr. Maxim Lyutikov spends a lot of his time pondering how these bursts could possibly be made, and all the data seems to point to the most extreme physics imaginable: neutron stars at the highest densities we can imagine, with extremely strong gravity and with a magnetic field a quadrillion times stronger than the Earth's magnetic field.

How do we know so much about supernovae, when all we see is this little point of light getting brighter and then dimmer over time? Given this minimal data, we can often say what type of star exploded, and even some details about how the explosion took place. Supernova astronomers are a lot like forensic scientists dusting for fingerprints and getting DNA samples at the scene of a crime. But instead of a typical crime scene, they are investigating the death of an entire solar system. Dr. Lindsey Kwok is a CIERA fellow at Northwestern University and an expert at using JWST to perform state-of-the-art forensic supernova science.

How big a computer do you need to simulate a supernova? Or a planet being formed? Or a black hole swallowing gas? Many astrophysicists spend their time developing computational models to simulate these systems and learn how they evolve. We discuss these computer simulations with Purdue Professor Dr. Paul Duffell. In this first episode of season 2, Dr. Abigail Polin takes over as host.

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 knw 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.

How did the galaxies form and how can we learn about them? Professor Erica Nelson of the University of Colorado, Boulder tells us how we use the James Webb Space Telescope (JWST) to look back in time and learn about the initial formation of structure in the universe.

How do stars explode? It turns out there's more than one way, and Professor Abigail Polin has discovered a totally new way that stars can end their lives. We talk with Professor Polin about how that works and how scientists look at a supernova to figure out what caused the explosion.