Results 261 to 270 of about 873,650 (292)

Heavy Elements in AP Stars

Publications of the Astronomical Society of the Pacific, 1970
Our material consists of eleven Ap stars of the Cr-Eu or Sr variety for which plate material obtained by H. W. Babcock was available. The plates were taken for magnetic field studies and generously loaned to the writers. We had only one spectrogram per star at our disposal, having a dispersion of 2, 8-4, 5, or 9 Â/mm.
E. Brandi, M. Jaschek
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Properties of Ap Stars in the Ultraviolet

International Astronomical Union Colloquium, 1976
The observational study of the “chemically peculiar (CP) stars of the upper main sequence” (Preston 1974) at wavelengths shortward of 3000 Å began early in this decade with Bernacca and Molnar's (1972) photometric observations of the helium-weak Bp stars and Molnar's (1973) investigation of α2CVn, both with the Wisconsin Experiment Package on 0A0-2 ...
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Rapid Oscillations of Ap Stars

Publications of the Astronomical Society of Japan, 1985
Abstract We interpret the rapid oscillations of Ap stars as a superposition of high overtone p-modes with the radial order n ≃ 30–40 and low degree l (l = 0–3). We have calculated the value of ν0≡2∫0Rc-1dr-1, which gives a good measure of the frequency separation of the consecutive overtones with a fixed value of l, for stellar ...
Hiromoto Shibahashi, Hideyuki Saio
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An Introduction to Ap Stars, roAp Stars and the Asteroseismology of roAp Stars

2000
The chemically peculiar (CP) stars of the upper main sequence are introduced with explanations of the nomenclature and the characteristics of the various sub-classes. The diffusion hypothesis is explained. A description of how diffusion accounts semi-quantitatively for the CP stars is given.
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Abundance Anomalies in am Stars and their Relation to Ap Stars

International Astronomical Union Colloquium, 1976
SummaryThe correlations of abundance anomalies of various elements in Am stars show continuous transition from normal through Am and Ap stars. There are poor correlations for some light elements and very good correlations for iron group and heavier elements.
V.L. Khokhlova, D.A. Ptitsyn
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The photometric variations of the Ap star HD34631

1991
The photometric behavior in the uvby system of the Ap star HD34631 has been reanalyzed on the basis of data collected over a time span of 16 years. A more accurate value of the period is deduced: P = 2.20269 +/-0.00004d. The lightcurves show a double-wave shape. The variations are smallest in the v band.
MANFROID J, RENSON P, CATALANO FA, LEONE, Francesco, VOGT N, FAUNDEZ M.   +5 more
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The Photometric Properties of the Ap Stars

International Astronomical Union Colloquium, 1976
The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical ...
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Ap/Bp Stars

2021
Swetlana Hubrig, Markus Schöller
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Uranium and thorium in Ap stars

1977
A recent revision of oscillator strengths for U II and T II makes it appear almost certain that there are some Ap stars for which the U/Th ratio is an order-of-magnitude (or more) greater than the meteoritic value. This ratio is expected for a recent r-process, which then predicts that uranium isotopes lighter than 238U would necessarily be present in ...
Cowley, C.R., Allen, M.S., Aikman, G.C.L.   +2 more
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A Metal-Poor Star With Abundances From a Pair-Instability Supernova

Nature, 2023
Han Zhanwen, Haining Li, Alexander Heger
exaly