On mode conversion and wave reflection in magnetic Ap stars
نویسندگان
چکیده
منابع مشابه
On mode conversion and wave reflection in magnetic Ap stars
We investigate the effect of a strong large scale magnetic field on the reflection of high frequency acoustic modes in rapidly oscillating Ap stars. To that end we consider a toy model composed of an isothermal atmosphere matched onto a polytropic interior and determine the numerical solution to the set of ideal magneto-hydrodynamic equations in a local plane-parallel approximation with constan...
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An arbitrary initial magnetic field in an A star evolves into a stable equilibrium. Simulations are presented of the formation of non-axisymmetric equilibria consisting of twisted flux tubes meandering under the surface of the star, and analytic arguments are given relating the stability and form of these equilibria. These results may help to explain observations of Ap stars with very non-dipol...
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We present new orbits for sixteen Ap spectroscopic binaries, four of which might in fact be Am stars, and give their orbital elements. Rough estimates of the individual masses of the components of HD 65339 (53 Cam) are given, combining our radial velocities with the results of speckle interferometry and with Hipparcos parallaxes. Considering the mass functions of 74 spectroscopic binaries from ...
متن کاملIsotopic anomaly and stratification of Ca in magnetic Ap stars
Aims. We have carried out an accurate investigation of the Ca isotopic composition and stratification in the atmospheres of 23 magnetic chemically peculiar (Ap) stars of different temperature and magnetic field strength. Methods. With the UVES spectrograph at the 8 m ESO VLT, we have obtained high-resolution spectra of Ap stars in the wavelength range 3000–10000 Å. Using a detailed spectrum syn...
متن کاملModelling element distributions in the atmospheres of magnetic Ap stars
Context. In recent papers convincing evidence has been presented for chemical stratification in Ap star atmospheres, and surface abundance maps have been shown to correlate with the magnetic field direction. Radiatively driven diffusion, which is known to be sensitive to the magnetic field strength and direction, is among the processes responsible for these inhomogeneities. Aims. Here we explor...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2008
ISSN: 0035-8711,1365-2966
DOI: 10.1111/j.1365-2966.2008.13062.x