91 research outputs found
Complex asteroseismology of the Slowly Pulsating B-type star HD74560
We present the results of complex seismic modelling of the Slowly Pulsating
B-type star HD74560. The star pulsates in five frequencies detected in
photometric observations. For all these frequencies, we identify the mode
degree, . For two of them, found also in spectroscopic data, we are able
to derived the empirical values of the complex nonadiabatic parameter . We
test effects of chemical composition and opacity data. Our results show that
the properties of seismic models of SPB stars differ significantly from those
of the more massive Cephei stars.Comment: 4 pages, 2 figures, conference proceedings, to appear in ASS
Complex asteroseismology of the Cep/SPB pulsator Eridani: constraints on opacities
We undertake another attempt towards seismic modelling of the most intensive
studied main sequence pulsators of the early B spectral type, Eridani.
Our analysis is extended by a requirement of fitting not only pulsational
frequencies but also the complex amplitude of the bolometric flux variation,
, related to each mode frequency. This approach, called {\it complex
asteroseismology}, provides a unique test of stellar parameters, atmospheres
and opacities. In particular, the concordance of the empirical and theoretical
values of we obtained for the high-order g mode opens a new gate in seismic
studies of the main-sequence hybrid pulsators. The most intriguing and
challenging result is that whereas an agreement of the theoretical and
empirical values of for the radial mode can be achieved only with the OPAL
data, a preference for the OP tables is derived from the analysis of the
high-order gravity mode.Comment: 10 pages, 9 figures, accepted for publication in MNRA
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