Colour and radial velocity variations in pulsating subluminous B stars

The utility of pulsations for the investigation of the structure and evolution of subdwarf B stars is considerable. However, the small number of detected modes generally limits the potential for a traditional seismological analysis such as that carried out for the Sun. Therefore, it is crucial to acquire additional primary data to characterise the stellar oscillations more completely. We review recent studies of radial velocity amplitudes and introduce new multi-colour photometry of small-amplitude sdBV stars. We also discuss a set of models for radial velocity and colour variations and demonstrate how these may be used to infer the spherical and azimuthal degrees of observed pulsations.