Oscillations in red giant stars
This material accompanies a
release on results from the Kepler mission that we have been published
as a Letter to Nature.
The figure below shows the sizes of red giant stars compared to the
Sun. Using the Kepler telescope, we have detected oscillations in hundreds
of red giant stars. The periods of those oscillations allowed us to study
the interiors of these giant stars, which represent the future life of our
The figure below shows the stages in the evolution of a star like the Sun.
The Sun itself is currently fusing hydrogen into helium in its core (lower
left). In later stages, when it becomes a red giant, the star will fuse
hydrogen in a shell around the helium core (2nd and 3rd figures). Finally,
the red giant will begin to fuse helium into carbon in its core (4th
Click to listen to the red giant
concert. This audio file was made by Daniel Huber, a PhD student at
the University of Sydney. You will hear oscillations based on actual
frequencies that were measured by the Kepler mission, sped up so as to be
audible to the human ear. Starting with the sound of a small red giant you
will gradually hear three stars of increasing size - each with lower
frequencies, but higher amplitudes - entering the "red giant concert"
Click to see Computer
animations by Paul Beck (K.U. Leuven, Belgium) showing mixed modes in