This artist’s concept shows how sound waves travel through a hypothetical star that has an orbiting planet.
Credits: Gabriel Pérez Díaz, Instituto de Astrofísica de Canarias
Credits: Gabriel Pérez Díaz, Instituto de Astrofísica de Canarias
We can’t hear it with our ears, but the stars in the sky are
performing a concert, one that never stops. The biggest stars make the
lowest, deepest sounds, like tubas and double basses. Small stars have
high-pitched voices, like celestial flutes. These virtuosos don’t just
play one "note" at a time, either -- our own Sun has thousands of
different sound waves bouncing around inside it at any given moment.
Understanding these stellar harmonies represents a revolution in
astronomy. By "listening" for stellar sound waves with telescopes,
scientists can figure out what stars are made of, how old they are, how
big they are and how they contribute to the evolution of our Milky Way
galaxy as a whole. The technique is called asteroseismology. Just as
earthquakes (or Earth’s seismic waves) tell us about the inside of
Earth, stellar waves -- resulting in vibrations or "star quakes" --
reveal the secret inner workings of stars.
NASA’s Kepler space telescope, now approaching the end of its
mission, has been a key player in that revolution, delivering
observations of waves in tens of thousands of stars since its 2009
launch.
NASA’s Transiting Exoplanet Survey Satellite (TESS), which
launched in April 2018, may observe sound waves in up to one million red
giants -- the massive, evolved stars that represent what our Sun will
look like in about 5 billion years. While both Kepler and TESS are most
famous for hunting for planets beyond our solar system (exoplanets),
they are also powerful, sensitive tools for detecting stellar
vibrations. And the more we know about stars, the more we know about
planets that orbit them.
Continue reading this story
Written by Elizabeth Landau
Editor: Tony Greicius
Source: NASA/Kleper and K2
