Solar‐like Oscillations in α Centauri B

Abstract

We have made velocity observations of the star α Centauri B from two sites, allowing us to identify 37 oscillation modes with l = 0-3. Fitting to these modes gives the large and small frequency separations as a function of frequency. The mode lifetime, as measured from the scatter of the oscillation frequencies about a smooth trend, is similar to that in the Sun. Limited observations of the star δ Pav show oscillations centered at 2.3 mHz, with peak amplitudes close to solar. We introduce a new method of measuring oscillation amplitudes from heavily smoothed power density spectra, from which we estimated amplitudes for α Cen α and B, β Hyi, δ Pav, and the Sun. We point out that the oscillation amplitudes may depend on which spectral lines are used for the velocity measurements.