2001A&A...378..142C

The G2 subgiant β Hyi (HR 98) was observed with the Coralie fiber-fed echelle spectrograph on the 1.2-m Swiss telescope at La Silla in June 2000. The resulting 971 high-accuracy radial velocities exhibit an rms scatter of 2.72m/s and a mean noise level in the amplitude spectrum of 0.122m/s. These measurements show significant excess in the power spectrum between 0.7-1.4mHz with 0.40m/s peak amplitude. Fitting the asymptotic relation to the power spectrum gives a large splitting of 58µHz which is in good agreement with theoretical expectations. Our data confirm the independent detection of solar-like oscillations in β Hyi announced by Bedding et al. (2001ApJ...549L.105B) which used the Ucles echelle spectrograph on the 3.9-m Anglo-Australian Telescope. Two independent instruments and calibration methods obtained very similar power excesses thus leaving little doubts on the stellar origin of the detected signal.