Solar-like oscillations in η Boo

Extract

We have observed evidence for p-mode oscillations in the G0 IV star η Boo (V = 2.68). This represents the first clear evidence of solar-like oscillations in a star other than the Sun. We used a new technique in which we measure fluctuations in the temperature of the star via their effect on the equivalent width of the Balmer lines. The observations were obtained over six nights with the 2.5 m Nordic Optical Telescope on La Palma and consist of 13000 low-dispersion spectra. The upper part of Fig. 1 shows the power spectrum of the equivalent-width measurements (the inset shows the window function).