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J. Arenas (Universidad de Concepcion)
This dissertation involves the study of three interacting binary stars: V603 Aql (Nova Aquilae 1918), BT Mon (Nova Monocerotis 1939) and UX UMa. UX UMa is the prototype-star of a major sub-class of nova-like systems. Using time-resolved spectroscopic data on V603 Aql, and time-resolved spectrophotometric data on UX UMa and BT Mon, I performed photometric and spectroscopic analyses, as well as Doppler tomographic studies and Eclipse mapping of these three CVs. In V603 Aql, I found evidence, for the first time in spectroscopy, for negative and positive superhump periods in the emission lines and the continuum. The superhump periods found in the continuum and line variations in V603 Aql are consistent with other, photometric, observations. The structure of the accretion disc in UX UMa, based on the models used in this dissertation, is characterized by two regions. An inner accretion disc which is characterized by a blue continuum with absorption lines, which cross over to emission with increasing disc radius. In the case of BT Mon, in my data, the system shows evidence of an accretion disc which is eclipsed by the secondary producing the broad eclipses observed, but a large fraction of the luminosity came from an accretion spot. This can explain the single-peaked emission lines observed in the spectra. Some authors have identified V603 Aql as permanent superhumper (PSH) based on the fact that the photometric period (Psh) is different from the spectroscopic period (Porb), and it has been suggested that the PSHs may represent a subgroup of CVs with mass ratios q<0.3 and high mass transfer rates. My results confirm that V603 Aql shows evidence of instabilities associated with the accretion disc which are the cause of the variations observed.