Delving into the private lives of stars has become a commonplace occurrence for paparazzi. A public presentation at Okanagan College in February 2008 took that fascination with the stars one step further when Dr. Jaymie Matthews, one of Canada’s foremost astronomers and a self-proclaimed astro-paparazzo takes the stage.
Matthews explained how he unveils the hidden lifestyles of stars by eavesdropping on “the music of the spheres.” He also described his version of an interstellar iPod — Canada’s first space telescope — Microvariability and Oscillations of Stars (MOST), which detects vibrations in the light of ringing stars too subtle to be seen even by the largest telescopes on Earth.
An astrophysicist and Mission Scientist leading the Canadian Space Agency’s MOST project, Matthews and his team of students and collaborators are writing a biography of our Sun – past and future – by studying its neighbours in the Milky Way.
Their research sometimes sounds more like astromedicine than astrophysics: performing ultrasound on stellar embryos, checking on the hyperactivity of a pre-teen sun, and taking the pulses of stars in their twilight years. They are also using MOST to forecast the weather on planets beyond the Solar System, and have begun the search for Terra Nova – exoEarths around other stars.
Matthews is eloquent in finding metaphors to illustrate the phenomena he studies. He once compared the rapid surface vibrations of a star to body language. Matthews and his colleagues have adapted the way geophysicists use seismic waves to explore the Earth’s structure. Applied to the study of stars, they call this new science stellar seismology or asteroseismology.
“We can’t put seismographs on the surface of the Sun or other stars, but we can see subtle effects of the waves as they cause the stellar surface to oscillate—they literally ring like gaseous bells,” explains Matthews. “The frequencies of the oscillations give us direct information on the gas through which the sound waves travel. We can use measurements of the composition of the star’s core as a clock to register its age.”