TESS Tunes into an All-sky ‘Symphony’ of Red Giants
Released on August 4, 2021
Using observations from NASA’s Transiting Exoplanet Survey Satellite (TESS), astronomers have identified an unprecedented all-sky collection of pulsating red giant stars that will aid in mapping the structure of our galaxy.
Sound waves traveling through any object – a guitar string, an organ pipe, or the interiors of Earth and the Sun – can reflect and interact, reinforcing some waves and canceling out others. This can result in orderly motion called standing waves, which create the tones in musical instruments.
Just below the surfaces of stars like the Sun, hot gas rises, cools, and then sinks, where it heats up again, much like a pan of boiling water on a hot stove. This motion produces waves of changing pressure – sound waves. Their interaction drives stable oscillations with periods of a few minutes that produce subtle brightness changes. For the Sun, these variations amount to a few parts per million. Giant stars with masses similar to the Sun’s pulsate much more slowly, and the corresponding brightness changes can be hundreds of times greater.
The physical differences between a cello and a violin produce their distinctive voices. Similarly, the stellar oscillations astronomers observe depend on each star’s interior structure, mass, and size. Studying them can help determine fundamental properties for large numbers of stars with accuracies not achievable in any other way.
Using TESS data for some 24 million stars, a team of astronomers led by Marc Hon at the University of Hawaii developed an AI system to identify 158,505 pulsating giants across the sky.
Credits
Francis Reddy (University of Maryland College Park): Lead Science Writer Chris Smith (KBRwyle): Lead Producer Chris Smith (KBRwyle): Animator Kristin Riebe (Leibniz Institute for Astrophysics Potsdam): Visualizer Daniel Huber (University of Hawaii, Honolulu): Scientist Marc Hon (University of Hawaii, Honolulu): Lead Scientist
Please give credit for this item to: NASA's Goddard Space Flight Center. However, individual items should be credited as indicated above.
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