Pulsation among Λ Bootis Stars
نویسندگان
چکیده
منابع مشابه
Mixing and Accretion in λ Bootis Stars
Strong evidence for deep mixing has been uncovered for slowly rotating F, and A stars of the main sequence. As the accretion/diffusion model for the formation of λ Bootis stars is heavily dependent on mixing in superficial regions, such deep mixing may have important repercussions on our understanding of these stars. It is shown that deep mixing at a level similar to that of FmAm stars increase...
متن کاملHow many λ Bootis stars are binaries ? ?
In the attempt to shed new light on the λ Boo phenomenon we analyzed the astrometric, photometric and spectroscopic characteristics of stars out of a list of recently selected λ Boo candidates. We show that the class is still ill-defined and discuss the possibility that some, if not most stars presently classified as λ Boo, are in fact binary pairs and that peculiar abundances may not correspon...
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The linear adiabatic pulsation-periods of Mira variable stars have been derived. Approximately 2701[1]models were calculated for M = 0.7 MΘ to 2 MΘ stars with radii from 180 RΘ to 340 RΘ and luminosities from 2800 LΘ to 10,000 LΘ. The chemical composition of all models is (X,Z) = (0.7,0.02). From the result of this study, linear relations on Luminosity-Period-Mass relationship and luminosity-pe...
متن کاملIdentification of λ Bootis stars using IUE spectra II. High resolution data
Stars included in the catalogue of λ Bootis stars by Paunzen et al. (1997) with high resolution spectra (FWHM: 0.10–0.25 Å) in the INES Archive of the International Ultraviolet Explorer satellite (IUE) are analyzed here in order to establish membership criteria for the λ Bootis group. Line-ratios of carbon to heavier elements (Si, Al, Ca) were adopted as criteria in the SWP range (1150–1980 Å)....
متن کاملOn the Λ Bootis Spectroscopic Binary Hypothesis
Is the proposed spectroscopic binary model able to explain the observed abundance pattern and photometric metallicity indices for the group members? What is the percentage of undetected spectroscopic binary systems? We have used the newest available stellar atmospheres to synthesize 105 hypothetical binary systems in the relevant astrophysical parameter range. These models were used to derive p...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 2000
ISSN: 0252-9211
DOI: 10.1017/s0252921100058590