A Search for Acoustic Oscillations on $\eta\ Cas$ with the Palomar 200'' Echelle Spectrograph
Session 111 -- Stellar Interiors
Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)

## [111.08] A Search for Acoustic Oscillations on $\eta\ Cas$ with the Palomar 200'' Echelle Spectrograph

M. Peri, K. Libbrecht (California Institute of Technology)

We have begun a program to observe acoustic oscillations in solar-type stars. Timeseries of radial velocity variations in the stellar absorption lines are acquired using the high-resolution echelle spectrograph on the Palomar 200'' telescope. These measurements are Fourier transformed to search for periodicities which are the key signature of p-mode oscillations. Initial tests indicate that our technique is likely to provide sufficient sensitivity to measure the sub-$m/s$ Doppler amplitudes predicted for the oscillations. Our first target star, $\eta\ Cas$ (G0 V, $m_v=3.44$), was observed during 6 nights in Aug-Sept 1993. We present results of those observations.