Some Insights into Stellar Structure from Nonlinear Pulsations

Nonlinear Pulsations of Convective Stellar Models

We review the numerical modelling of the nonlinear pulsations of classical variable stars with hydrocodes that include the effects of turbulent convection. Despite their simplicity these turbulent convective recipes appear to remove many of the difficulties that radiative codes faced. In particular, the numerical modelling of double mode pulsations has become possible.

Non - Radial Pulsations and Large - Scale Structure in Stellar Winds

Almost all early-type stars show Discrete Absorption Components (DACs) in their ultraviolet spectral lines. These can be attributed to Co-rotating Interaction Regions (CIRs): large-scale spiral-shaped structures that sweep through the stellar wind. We used the Zeus hydrodynamical code to model the CIRs. In the model, the CIRs are caused by " spots " on the stellar surface. Through the radiative...

RADIATIVE OPACITIES AND STEllAR PULSATIONS

Insights into Biomolecular Structure from Theoretical Spectroscopy

The first part of the present PhD thesis is concerned with the reaction mechanism of Cytochrome P450 NO reductase. Two important aspects of this enzyme are studied. 1) The structural and electronic nature of the key intermediate I and 2) the unusual direct reduction of the active site by NADH. In the computational study the inclusion of the entire enzyme structure is important. For that purpose...

Stellar pulsations excited by a scattered mass

We compute the energy spectra of the gravitational signals emitted when a mass m0 is scattered by the gravitational field of a star of mass M >> m0. We show that, unlike black holes in similar processes, the quasi-normal modes of the star are excited, and that the amount of energy emitted in these modes depends on how close the exciting mass can get to the star. PACS numbers: 04.30.-w, 04.40.Dg...