Results 141 to 150 of about 650 (183)

Circumstellar matter and the nature of the SN1987A progenitor star

Nature, 1987
It is argued that radio observations of the supernova 1987A can be interpreted in terms of its interaction with circumstellar matter. The early turn-on of the radio emission implies a relatively low density circumstellar medium. The optical properties of the supernova imply that the progenitor star had a smaller radius than that of a typical type II ...
Claes Fransson, Chevalier R A
exaly   +2 more sources

Circumstellar Matter in Direct Impact Algol Systems

Astrophysics and Space Science, 1995
Full-orbit Hα observations have been analyzed to determine the two-dimensional distribution of the circumstellar gas in the four short-period Algols, U Sge, U CrB, RS Vul, and SW Cyg. In these systems, the gas stream resulting from Roche-lobe overflow directly impacts the mass-gaining star and feeds material into a structure known as a ‘transient ...
Geary E. Albright, Mercedes T. Richards
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Circumstellar matter in the symbiotic binary EG and

Astrophysics and Space Science, 1993
We present a quantitative model of a proposed common slowly expanding envelope corotating with a symbiotic binary system. The geometry of the envelope is defined by the equipotential surface containing the Lagrangian pointL 2. The model was applied to the symbiotic binary EG And.
A. Skopal, A. Vittone, L. Errico
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Circumstellar Matter in Selected Symbiotic Stars

Astrophysics and Space Science, 1995
A group of symbiotic binaries exhibits periodic variation in the optical continuum during orbital motion. It is suggested that this variation can be produced by different projection of the circumstellar matter, located in major part between the components of the binary, into the line of sight at different orbital phases.
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Modifications and erosion of circumstellar matter by wind particles

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987
Erosion effects and chemical modifications induced by the bombardment of circumstellar solids by wind particles around low mass stars is considered. Two different evolutionary phases have been investigated: i) explosive phases, modelled as FU Orionis type bursts, during the contraction toward the main sequence; ii) the red giant stage in which stars ...
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Interaction of Supernovae with Circumstellar Matter

1990
Stars of essentially all masses are known to lose mass during their evolution. The mass loss characteristics at any time are determined by the evolutionary status of the star. The region around a star that is modified by these processes is referred to as the circumstellar medium.
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Chemical Evolution of Circumstellar Matter around Young Stellar Objects

Astrophysics and Space Science, 1995
Recent observational studies of the chemical composition of circumstellar matter around both high- and low-mass young stellar objects are reviewed. The molecular abundances are found to be a strong function of evolutionary state, but not of system mass or luminosity. The data are discussed with reference to recent theoretical models.
van Dishoeck, Ewine F., Blake, Geoffrey A.   +1 more
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Circumstellar matter in Herbig AeBe stars

Infrared Physics & Technology, 1994
Abstract I briefly summarize the observational evidence for large envelopes in the immediate environment of Herbig AeBe stars, and the results of star + envelope models. Then, I discuss two alternative possibilities to account for the observed mid-infrared fluxes, namely as the emission of very small grains (VSG) and policyclic aromatic hydrocarbons (
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Interaction of Supernova Eject with Interstellar and Circumstellar Matter

Annals of the New York Academy of Sciences, 1984
The series of one-dimensional numerical simulations of supernova ejecta interactions with both interstellar and circumstellar matter whose results are presented was prompted by Chevalier's (1982) indication that the late time behavior of such interactions can be modeled by certain exact analytic self-similar solutions corresponding to ideal gas spheres
E. P. LIANG, R. A. CHEVALIER
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The Shape of the Extinction Curve of Opaque Circumstellar Matter

1996
The extinction curves observed in the spectra of Be stars, characterized by stellar emission of both hydrogen and helium lines, show several peculiarities. The extinction bump near 2200 A is apparently absent in the extinction law of the circumstellar dust grains.
Walter Wegner, Jacek Krełowski
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