Spectrographic observations made in the course of a search for solar-like acoustic oscillations in Alpha Cen A are described. The observational method was to search for periodic Doppler-shift variations in all of the spectrum lines within the wavelength range accessible to a high-dispersion echelle spectrograph - about 30 nm centered on 427.5 nm, in this case. A search was also conducted for variations in the ratio of line core to continuum intensity, again averaged over all the available lines. No convincing oscillations were found in either case, with upper limits for typical single oscillation modes of 70 cm/s in Doppler shift and 4 x 10 to the -5th for continuum intensity variations inferred from line core intensities.
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Brown et al. (1990) studied this question.