Identification of pulsation modes from photometry

Abstract

AbstractThe identification of the detected pulsation modes in terms of the spherical harmonic quantum numbers is crucial for asteroseismology. Light curves obtained in different passbands have become an important tool for mode identifications, which rely on wavelength-dependent amplitudes and phase shifts. We demonstrate this for different types of pulsators and review recent successes from earth-based measurements, especially in determining the important l values. The extensive amount of accurate data needed to determine small phase shifts and accurate amplitude ratios suggests multicolor measurements using space satellites. This motivated the multicolor BRITE satellite project, for which the first two satellites have already been launched successfully. We demonstrate the potential from models computed for the BRITE wavelengths. Most of the excellent presently available satellite photometry is not multicolor, although frequencies with amplitudes as small as a few parts-per-million have been detected and confirmed. We briefly discuss mode identifications from frequency patterns, including the use of correlations between phase and amplitude changes.