Asteroseismology from equivalent widths: a test of the sun


Kjeldsen et al. (1995) reported a probable detection of solar-like, low- amplitude, p-mode oscillations of eta Bootes using equivalent width measurements from low-resolution spectra of the hydrogen Balmer lines. We tested the usefulness of this technique using observations of the Sun in integrated light. Despite the very high signal-to-noise ratio of the data stretching over six continuous days, no solar oscillation signal was found so far in the equivalent width of Hensuremathβ. Spatially resolved observations of the Hensuremathβ equivalent width at solar disk center reveal that the oscillation signal is suppressed in the wings of Hensuremathβ as compared to the continuum. Extrapolation of the oscillation signal seen in the spatially resolved data suggests an amplitude of about 1ppm for integrated light measurements, which is about a factor of 5 lower than expected from simple theoretical arguments. We explore other methods to deduce an oscillation signal from all spectral lines simultaneously. cont has: Deng, L. et al.; auths fixed below

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