This thesis has analysed spectroscopic data for three stars in detail, the β Cephei star V2052 Ophiuchus, the γ Doradus star QW Puppis and the γ Doradus candidate star HD139095. Twelve other candidate γ Doradus stars have had their Vrotsin i, binary status and, where possible, the presence of line profile variation determined. A new technique utilising scaled delta functions has been developed to allow the extraction of a single, high S/N line profile from a high resolution and large wavelength range spectrum. This procedure has performed well in the γ Doradus stars examined. The application of the new mode identification technique, the Fourier Parameter Fit method, to the three stars examined in detail has been very successful. For each of the three stars constraints have been placed on the degree (l) and the azimuthal order (m) of the non-radial pulsation modes detected.

Three γ Doradus-type stars are analysed: HD139095, HD153580, and HD197541. Long-term observation campaigns have been conducted on each star, with over 300 spectra of each star being gathered for analysis using the HERCULES spectrograph at Mount John University Observatory. For each star, cross-correlation techniques were used to obtain representative line profiles for each spectrum. The analysis of these line profiles has resulted in frequency and pulsation mode identifications for these three stars. Abundance analysis has also been performed on HD139095 and HD197541, and their fundamental parameters are confirmed as being consistent with the γ Doradus class of stars. HD153580 and HD197541, previously only candidates for the class, can now be classified as bona fide γ Doradus type stars. The frequencies and modes identified in this thesis will be very useful in constraining future theoretical models, allowing us to better understand and model the interiors of γ Doradus stars.

This thesis has analysed spectroscopic data for three stars in detail, the β Cephei star V2052 Ophiuchus, the γ Doradus star QW Puppis and the γ Doradus candidate star HD139095. Twelve other candidate γ Doradus stars have had their Vrotsin i, binary status and, where possible, the presence of line profile variation determined. A new technique utilising scaled delta functions has been developed to allow the extraction of a single, high S/N line profile from a high resolution and large wavelength range spectrum. This procedure has performed well in the γ Doradus stars examined. The application of the new mode identification technique, the Fourier Parameter Fit method, to the three stars examined in detail has been very successful. For each of the three stars constraints have been placed on the degree (l) and the azimuthal order (m) of the non-radial pulsation modes detected.