Results 131 to 140 of about 334 (164)

Stellar chromospheric temperatures

Astrophysics and Space Science, 1983
The emission doublet 2800 Mgii of stellar chromospheric origin is always stronger than the emission in the Lα line of hydrogen. At the same time, the ratio of their fluxes,Q=F(Mgii)/F(Lα), varies over a wide range— from 2 up to 20 in stars of one and the same type.
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Stellar Chromospheres, Coronae, and Winds

1986
The three subjects listed in the title of this chapter were originally defined for phenomena that are observed in the Sun. Observations of other stars have now been made at a wide range of wavelengths and have revealed that one or more of these phenomena are present in stars of every class.
J. P. Cassinelli, K. B. MacGregor
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Stellar Chromospheres, Coronae, and Winds (Invited Review)

Astrophysics and Space Science, 1986
Within the last few years there have been important advances in our understanding of the chromospheres, coronae, and winds of late-type stars. This progress has been the result of ultraviolet and X-ray observations obtained from space with the International Ultraviolet Explorer andEinstein satellites. In addition, ground-based astronomy has contributed
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Stellar Model Chromospheres and Spectroscopic Diagnostics

Annual Review of Astronomy and Astrophysics, 2017
The discovery of exoplanets and the desire to understand their atmospheric chemical composition and habitability provides a new rationale for understanding the radiation from X-rays to radio wavelengths emitted by their host stars. Semiempirical models of stellar atmospheres that include accurate treatment of radiative transfer of all important atoms ...
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Solar and stellar chromospheres

2005
This review attempts to highlight two fundamental and complementary aspects of the chromospheric phenomenon; viz., global properties of stellar chromospheres and their variation among the stars, and the underlying fine structure that affects or determines these global properties.
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Stellar Chromospheres, Coronae, and Winds

1992
Chromospheres, coronae, and winds similar to those observed on the Sun have been detected in a variety of cool stars. In many cases, especially for main-sequence stars, there is good evidence that the processes leading to non-radiative plasma heating and wind acceleration are the same as for the Sun, although the radiative losses from stellar ...
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Diagnostics of Stellar Chromospheres and Transition Regions

, 1999
A. C. Lanzafame
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Stellar chromospheres.

Science (New York, N.Y.), 2010
Besides being of intrinsic interest, these outer stellar envelopes provide very useful astrophysical tools. ; © 1966 American Association for the Advancement of Science.
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Chromospheric Lines as Diagnostics of Stellar Oscillations

2008
Gravitational waves in the chromosphere, theorized as early as 1963 [10], are thoroughly explored in the more recent papers by [7, 8]. Theory predicts that the convective overshoot in the upper photosphere and low chromosphere will readily excite gravity waves.
Diane B. Paulson, W. Dean Pesnell, L. Drake Deming, Martin Snow, Travis S. Metcalfe, Tom Woods, Brigette Hesman   +6 more
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Stellar Chromospheres: The Source of UV Emission

2019
The lower layer of a star’s atmosphere, its photosphere, has a thermal structure that decreases outward controlled by the balance of radiative and convection heat from below and the loss of radiation to space. With increasing height in a stellar atmosphere, magnetic heating processes become important in the energy balance, forcing the temperature to ...
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