SIMULATIONS OF STELLAR RADIAL-VELOCITY AND SPECTRAL-LINE BISECTOR VARIATIONS .1. NONRADIAL PULSATIONS

The radial-velocity and spectral variations are calculated for low-amp litude nonradial pulsations in slowly rotating stars (v sin i=3 km s(- 1)). Sectoral modes (l=-m) in the range l=1-8 are considered. An empir ical equation relating the pulsational amplitude to the ''observed'' s tellar radial-velocity amplitude is derived and this indicates that pr ecise radial-velocity techniques should be able to detect low-amplitud e (<1 km s(-1)) pulsations for sectoral modes as high as l=6. The spec tral variations manifest themselves via changes in the span and curvat ure of the line bisector which are maximized for m=4. These spectral v ariations can be used to distinguish between radial-velocity variation s due to pulsations from those due to the reflex motion of the star ca used by the presence of a low-mass companion. However, these measureme nts require data taken at high resolution (lambda/Delta lambda>100,000 ) and high signal-to-noise ratios (S/N>500).