| Popis: |
Accurate determination of fundamental stellar properties is crucial in understanding and testing models of stellar structure and evolution. To date, most stars with independent determinations of stellar properties based on high-resolution observations by optical interferometers belong to stars of type F5 or later, and most of measurements for early type stars come almost exclusively from the seminal observations with the Narrabri Stellar Intensity Interferometer (NSII) 50 years ago. Additionally, stellar rotation, generally overlooked in standard stellar models for decades, can play a central role for early-type stars, given their frequent high rotation rates. In this case, determination of fundamental stellar properties requires accurate diameter estimates at a range of position angles, and a more detailed modelling of the stellar surface. Recent development of 2D stellar models including a self-consistent rotation description (incorporating differential rotation) in stars with radiative envelopes has provided a method to describe the effects of rotation that links them to fundamental properties,based on a small set of parameters determining the stellar structure (mass,composition,rotation). In this thesis I have determined fundamental stellar properties for 14 new stars with spectral types earlier than F6. For 10 of them, the effects of stellar rotation may be neglected, whereas the other 4 exhibit fast rotation. In order to derive stellar parameters for these stars, I have incorporated state-of-the-art 2D models into a code capable of generating a model synthesizing all observables into a robust and self-consistent framework. Using interferometry,star distances,photometry and spectroscopy in the ultraviolet,visible and infrared, the derived fundamental stellar parameters, together with rotation dependent evolutionary tracks,are used to determine mass and age of the stars,corrected for the bias induced by the star rotation axis orientation. |
