March 24, 2015

Science: The stellar seismology

CoRoT Scientific Programme

The stellar seismology

The purpose of stellar seismology is to analyse the vibration modes of the stars which, submitted to forces of gravity, pressure and Coriolis, behave as oscillators with many specific modes. The eigen frequency (between 1 minute and 3 hours), the amplitude (a few ppm in Fourier space) and the lifetime (a few days) of these modes make it possible to determine some important parameters of stellar physics, such as the size and the composition of the core, the limits between radiative and convective zones, or the internal profile of rotation. These oscillating modes, which generate variations of luminosity at the surface of the star, are the only information, with neutrinos, coming from the depth of the stars. Acquired and collected on stars with different mass, age and chemical composition, the CoRoT light curves bring a significant amount of data of a new kind about stellar evolution.
During the whole mission 150 stars will be observed, with magnitude between 6 and 9.