That rings a bell: Professor studies stars’ vibrations using space telescope

Dr. Michael Reed can distinctly remember when he became interested in the universe and its contents: the moon landings in the summer of 1969.

“I remember those very clearly, mostly for how boring they were,” said Reed, professor of astronomy at Missouri State University. “You waited forever for them to have a two-minute video, which was horribly fuzzy.”

Despite the lack of entertainment he seemed to get from watching the landings, they were one of the first things he thought of when deciding what to study in college. The rest, as they say, is history.

The “sounds” of sweet harmony

“Imagine you’re listening to an orchestra. Every instrument has its own set of sounds, and stars are just like that.” — Dr. Michael Reed

With help from funding through NASA and the National Science Foundation (NSF), Reed is currently studying how stars vibrate with help from NASA’s Kepler spacecraft. This space telescope orbits the sun, and in its original mission, observed one set of stars, taking a picture every minute, for four years. Now in its extended mission, it looks at a different set of stars every 90 days, providing the most accurate data ever obtained with accuracies down to one part in a million.

Reed and his team analyze these images to see the stars’ vibrations and discover what is going on inside.

“Imagine you’re listening to an orchestra,” said Reed. “Every instrument has its own set of sounds, and stars are just like that. They have a whole bunch of variations within them, and each of those variations tells you something about a different region inside of the star.”

Reed then classifies the different vibrations, or instruments, coming from the star. But how does learning about these vibrations help us here on Earth?

“These are stars that our sun will be like in another five billion years,” said Reed. “By understanding these stars, we can understand what’s going to happen to our solar system and the environment of our solar neighborhood in the far future.”

Getting good vibrations from Kepler

Kepler was launched in March 2009 with a mission to discover new planets over a four year time frame. The telescope was able to discover these planets when they passed in front of stars, causing a light blockage known as the transit. Unfortunately, researchers cannot tell how big a planet is unless they know how big the star is. That’s where Reed’s research comes in.

“Only in the cases that the star is pulsating, known as a variable star, do they know the size of the star because asteroseismology tells you that based on its vibrations,” said Reed. “That, in turn, gives you the size of the planet.”

Researchers, such as Reed, who are outside of NASA, are able to apply for observations during Kepler’s extended mission. In other words, an astronomer can ask NASA, “Could you focus on this star for a while?” So far, Reed’s observing programs have been approved during each extended campaign.

A game changer

“In the big picture, nothing has advanced asteroseismology as much as Kepler….” — Dr. Michael Reed

Over the last 10 years, Reed has received more than $1.2 million in funding to advance his research. His collaborative team has published more than 15 papers where they have unveiled differences in the chemical stratification within these stars, discovered stars with close companions, and even one which spins more slowly in the center than at the surface.

“In the big picture, nothing has advanced asteroseismology as much as Kepler, quite frankly,” said Reed. “Our knowledge of the insides of stars has really gained huge ground from this spacecraft. Observing in that way has profoundly changed our view of the universe.”

Reed’s collaborative team, which consists of fellow professors, graduate and undergraduate students, received their most recent transmission of data in July 2015. The team will process and analyze these data, possibly helping the science community learn more about helium fusion, planets outside our solar system and our solar neighborhood as a whole.