The A-Star Puzzle IAUS 224, Poprad, Slovakya, 08 Temmuz 2004, cilt.224, ss.81-88
Double-lined-eclipsing binaries are the essential systems for the measurement of
stellar masses and radii. About 50-60 systems have components (mostly A-stars) for which
these values are known with an uncertainty less than 1-2%. Therefore, these systems are very
suitable to improve our understanding of stellar structure and evolution. In this paper, special
attention is given to the assessment of the role of internal rotation of the early-type stars in
selected double-lined binaries (i.e., EK Cep, PV Cas, and θ
2 Tau): it is shown that adoption of
rapidly rotating cores for such stars permits the models to be in very good agreement with the
observational results including the apsidal advance rates.