Results 181 to 190 of about 40,765 (217)

Interstellar Extinction by Quartz Grains

Nature, 1968
Interstellar extinction cross sections calculated for quartz particles, results indicate quartz is not appreciable component of interstellar ...
K. S. KRISHNA SWAMY, N. C. WICKRAMASINGHE   +1 more
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Extinction by Interstellar Silica Grains

Nature, 1968
INTEREST has recently been expressed in the possibility that the interstellar dust contains a silica component (ref. 1, and R. C. Gilman, private communication). The purpose of this communication is to point out that silicon dioxide has strong absorptions in the 8–14µ atmospheric “window” which should be observable with ground-based infrared telescopes.
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A Model for Interstellar Extinction

Astrophysics and Space Science, 1982
From an analysis of the interstellar extinction we conclude that interstellar grains are of three main kinds: graphite spheres of radii ∼0.02 μm making up ∼10% of the total grain mass, small dielectric spheres of radius about 0.04 μm making up ∼25% of the mass, and hollow dielectric cylinders containing metallic iron with diameters of ∼2/3 μm making up
F. Hoyle, N.C. Wickramasinghe
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Interstellar Extinction by Graphite Grains

Nature, 1965
N. C. WICKRAMASINGHE, C. GUILLAUME
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Buckminster Fullerene and Interstellar Extinction

Acta Astronomica, 2023
Most of over 500 Diffuse Interstellar Bands (DIBs) can not be assigned to any carrier. Only the infrared DIBs at 9348-9632 Å are known to be absorption lines of the buckminster fullerene cation C60+. We show that equivalent width of the 9577 Å DIB is correlated with the bump area on the ultraviolet extinction curve and with interstellar reddening E(B-V)
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The interstellar extinction curve

Publications of the Astronomical Society of the Pacific, 1993
The history of the study of interstellar extinction is briefly discussed. The methods used to determine the extinction law are presented and compared, and the main difficulties involving the application of certain methods are shown. This paper emphasizes the necessity of investigating single-clou extinction curves instead of ill-defined long distance ...
J. Krelowski, J. Papaj
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Interstellar Dust and Extinction

Annual Review of Astronomy and Astrophysics, 1987
The ultraviolet (UV) region of the spectrum has been crucial in providing information on the nature of the material and size distribution of the particles of interstellar dust. Before there were any measurements of the UV properties of interstellar extinction, interstellar particles were believed to be composed primarily of dirty ices.
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Interstellar Extinction II

1987
Matter is present in the Galaxy not only in the form of stars. Characteristic absorption lines in all wavelength ranges reveal the presence of gas scattered throughout space between stars. In addition to the gas, Trumpler has shown that in the galactic disk, dust produces a dimming of the light coming from distant stars, and modifies the energy ...
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Interstellar Extinction and Polarisation

1991
In Chapter 1 we referred briefly to the early measurements of interstellar extinction over the UBV wavelength range that gave an approximately 1/λ extinction coefficient amounting typically to ~ 1–2 mag/kpc. We now discuss both extinction and polarisation observations in more detail with a view to using this data as discriminants for grain models in ...
F. Hoyle, N. C. Wickramasinghe
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Interstellar Extinction (L)

1969
Many observations became understandable only when astronomers realized that there are huge clouds of gas and dust in interstellar space, by which the light of far-off stars is dimmed and reddened. In order to reduce our observations for this effect, we have to find how this extinction depends on wavelength; our results will also help to understand the ...
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