The Pulse Of Distant Stars

摘要

Far from being a constant light source, the Sun oscillates at thousands of different frequencies simultaneously and has granulations at its surface associated with rising and falling fluid elements. Despite the amplitudes of the induced light variations being at a level of about one part per million, the Sun's brightness has allowed its "pulse," in terms of luminosity variations, to be measured using Earth-based telescopes. On page 558 of this issue, Michel et al. (1) present data from the space satellite CoRoT (Convection Rotation and Planetary Transits), demonstrating the ability to characterize the oscillation amplitudes and the signature of stellar granulation in three other stars. In addition to the technical success that this represents, the measurements show that solar-like oscillations do occur in these stars, although with somewhat smaller amplitudes than predicted. This bodes well for the future of space-based seismology programs while simultaneously challenging us to refine our models of these stars.