Logo ASU
Astronomical Institute 
Academy of Sciences of the Czech Republic
Logo AV

 

Public lecture January 10, 2005


We invite you to the public lecture in Astronomical Institute, Academy of Science of the Czech Republic

Monday January 10, 2005
13:00

in new lecture room in Astronomical Institute Ondrejov
 
 

An observational study of line-profile variable B stars in multiple systems

Dr. Katrien Uytterhoeven


We present the results of the analysis of the pulsational behaviour of the line-profile variable binary components of kappa Scorpii, lambda Scorpii and epsilon Lupi.

Our research is situated in framework of a systematic long-term project of line-profile variable B stars in close binary systems, with the aim to search for tidally induced oscillations. Major unsolved questions in the understanding of stars concern the role, if any, of binarity and rotation on stellar pulsation-mode selection and on the enhancement of pulsation-mode amplitudes.

We also studied the line-profile variations of the confirmed beta Cephei stars kappa Scorpii and lambda Scorpii in detail in the broader context of a seismic study. As the interior of stars is not directly observable, accurate information is gathered from  stellar oscillations which penetrate deep inside the star and whose behaviour is uniquely determined by the properties of the overall stellar structure. It is of utmost importance to identify with accuracy the pulsational frequencies and wavenumbers of the pulsation modes.

High-resolution spectroscopy allows a detailed analysis of small line-profile changes. Techniques have been proposed to disentangle composite spectra, one of them being the KOREL code. It is unclear if the line-profile variability is preserved well after disentangling. We tested the performance of KOREL by means of the testcase kappa Scorpii.
 
 

Vladimir Karas
organizer