by Veronika Meduna
Universityof Canterbury astronomers Peter Cottrell and Karen Pollard with astronomy stamps issued by New Zealand Post. (image: University of Canterbury)
Although modern telescopes are reaching closer and closer to the edge of the observable universe and the beginning of time, the inside of stars remains very difficult to explore. Yet, the interiors of stars are the crucibles for all known elements except hydrogen and helium.
One way to investigate the internal structure of stars and their evolution is to listen to their "music". Many stars, including our sun, vibrate like bells or a drum that has been struck. The pattern of surface vibrations depends on the internal properties of the star and as a result each star has a unique musical voice. University of Canterbury astronomers Karen Pollard and Peter Cottrell and PhD students Florian Maisonneuve and Emily Brunsden explain how the analysis of such tiny surface vibrations - a scientific discipline called asteroseismology - is used to deduce information about the stellar core. The team uses telescopes at the Mt John Observatory near Tekapo to observe stars and, in collaboration with other observatories, has set up an astereroseismic network to study the structure and evolution of several groups of pulsating stars.