Asteroseismology via Equivalent Widths -- Tests on Procyon, Eta Bootes, and Alpha Triangulum


Recently, Kjeldsen et al. 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 H Balmer lines. This technique has the potential to provide stellar oscillation measurements good enough to allow the asteroseismic inference of stellar structure. Here we report on the preliminary analysis of data from three observing runs with the Kitt Peak Coude Feed and 2.1-m telescope in November 1995 (Alpha Triangulum), February 1996 (Procyon), and March 1996 (Eta Bootes). These runs are being used to develop observing and data reduction techniques, such as a synchronized timing system to maintain evenly spaced temporal samples, a continuous unshuttered CCD readout to increase the duty cycle of the observations, and a simulation of the probability of a detection as a function of observing run length. We observed the region around the H beta, gamma, and delta lines with a spectral dispersion of about 0.4 Angstroms per pixel, extracted equivalent widths, and performed time series analysis. The temporal spectrum of Alpha Triangulum contains a significant peak near the theoretical prediction, however, we do not yet know the origin of this peak.

American Astronomical Society Meeting Abstracts #188