Office Hours with… Earl Bellinger

In an interview, Yale astronomer Earl Bellinger discusses the interiors of stars and the music they make.

Earl Bellinger, an assistant professor of astronomy in Yale’s Faculty of Arts and Sciences, has spent more than a decade traveling the world, using math to peer inside stars, and playing music.

His academic pursuits have taken him to Japan, India, Brazil, Germany, Denmark, and Australia, while also pulling him into the orbit of MESA, the open-source stellar simulation software, and PLATO, the upcoming space mission that will measure the pulsations of millions of stars.

Now Bellinger is at Yale — still tracking stellar pulsations, still making music — and he says there’s nowhere he’d rather be. He leads the Yale Astro Machine Learning Group and is a member of the Institute for Foundations of Data Science.

In the latest edition of Office Hours, a Q&A series that introduces new Yale faculty members to the broader community, Bellinger talks about what led him to study astronomy, his love of computers, and the music of stars.

What came first for you, computers or astronomy?

Earl Bellinger: I have always loved computers and computer programming. I started teaching myself how to program at around seven years old. I have an older brother who was also interested in technology, so when we got a computer, I sat by his side and watched him navigate the early Internet. I would stay up all night trying to learn how to write programs.

When did astronomy enter the picture?

Bellinger: As an undergrad at SUNY-Oswego, in my first-year physics seminar, we had a guest lecturer who was an astronomer working on pulsating stars. That led to me working with him, and what eventually became my undergraduate research thesis.

And I did have a profound experience at an observatory. I went to Brazil during the summer, as an undergrad, where I spent a week on top of a mountain. There was no light pollution, and you could see the Milky Way in extraordinary detail. It remains the most beautiful thing I’ve ever seen in my life. When I got to grad school, I knew that I loved scientific computing and machine learning, but I didn’t know how I wanted to apply it. I went around and worked in a lot of different fields and realized that I love astronomy. Astronomy is my true love.

All the pieces of the puzzle are there in astronomy that make it truly enjoyable. I love that it tells us about our place in the universe. That’s always been a big question on my mind. How is it humanity is here? What is the fate and history of the universe?

How would you describe your research?

Bellinger: Broadly speaking, I work on pulsating stars. What most people don’t appreciate is that pretty much every star is a pulsating star, including our own sun, but the pulsations are so slight we didn’t know our sun was pulsating until the 1960s.

These pulsations are sound waves, so in a way, stars are making music for us. We can see that music in the brightness of a star going up and down ever so slightly. And when you analyze that data, you can pull out the actual frequencies of the star, which reveal information about the internal structure of the star. It’s called asteroseismology.

What I do is look inside stars and figure out how old they are, as well as other things. It allows us to determine whether our models of how stars and galaxies evolve are accurate.

Do you use MESA in this work?

Bellinger: Yes, it’s an amazing piece of software — an open-source stellar evolution code. You can enter in the conditions of a star, such as its mass, its chemistry, or other physics, and MESA will produce a simulation of how that star will live its life. It calculates billions of years of evolution in about five minutes!

Lastly, let’s talk about something you have in common with the stars. You both make music, yes?

Bellinger: I play any instrument I can get my hands on, mostly guitar, bass, and drums but also piano, cello, ukulele, dulcimer. Basically anything. When I was 14, I self-studied music theory, and as a teenager I wrote maybe 100 pieces.

In my 20s I got interested in music production, the idea of recording a piece and making it sound good. And so now I have a home recording studio. I go back and grab these songs I wrote as a teenager, learn them again, and record them with me playing all the instruments. And I put them out on the web.

They can be described as post-rock. I take the instruments of rock music and do something that doesn’t conform to the standards of the genre, typically with no vocals. It’s a lot like abstract art.

Article by Jim Shelton, YaleNews