Results 1 to 10 of about 269 (256)
Measuring the magnetic fields in the chromospheres of low-mass stars [PDF]
Nature CommunicationsMagnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these stars. However,
Tianqi Cang +13 more
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On the sizes of stellar X-ray coronae [PDF]
Astronomy and Astrophysics, 2004 Spatial information from stellar X-ray coronae can be inferred by use of scaling laws from the solar corona. This requires measurement of the physical parameters temperature and density. We concentrate on the newly available density measurements from line fluxes of X-ray lines measured for a large sample of 64 grating spectra of 42 stellar coronae ...
J -U Ness, M Gudel, J H M M Schmitt
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Radiative plasma simulations of black hole accretion flow coronae in the hard and soft states [PDF]
Nature CommunicationsStellar-mass black holes in x-ray binary systems are powered by mass transfer from a companion star. The accreted gas forms an accretion disk around the black hole and emits x-ray radiation in two distinct modes: hard and soft state.
Joonas Nättilä
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Flare Heating in Stellar Coronae
Astrophysical Journal, 2002 We investigate the contribution of very weak flares to the coronal luminosity of low-mass active stars. We analyze EUVE/DS events data from FK Aqr, V1054 Oph, and AD Leo and conclude that in all these cases the coronal emission is dominated by flares to such an extent that in some cases the entire emission may be ascribed to flare heating.
Vinay L Kashyap, M Gudel, Marc Audard
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X-ray astronomy of stellar coronae [PDF]
Astronomy and Astrophysics Review, 2004 X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars, yet many fundamental mechanisms operating in their magnetic fields still elude an interpretation through a ...
M Gudel, Gudel Manuel
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Heating of the solar and stellar coronae: a review [PDF]
Astronomische Nachrichten, 2007 AbstractDespite great advances in observations and modelling, the problem of solar and stellar heating still remains one of the most challenging problems of space physics. To find a definite answer to what sort of mechanisms act to heat the plasma to a few million degrees requires a collaborative effort of small scales observations, large capacity ...
R Erdelyi, I Ballai
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On Stellar Coronae and Solar Active Regions
Astrophysical Journal, 2000 Based on Yohkoh Soft X-Ray Telescope (SXT) observations of the Sun near peak activity level obtained on 1992 January 6, we search for coronal structures that have emission measure distributions EM(T ) that match the observed stellar coronal emission measure distributions derived for the intermediate-activity stars v Eri (K2 V) and m Boo A (G8 V) from ...
G Peres, S Orlando, J Martin Laming
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Coronal Loops with Different Metallicities and Generalized RTV Scaling Laws
The Astrophysical Journal, 2023 Stellar metallicity is a critical factor to characterize the stellar coronae because it directly affects the radiative energy loss from the atmosphere.
Haruka Washinoue, Takeru K. Suzuki
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Symposium - International Astronomical Union, 1979 A new method of calculating models for stellar coronae is being developed with the aim of providing models of coronae around hot stars capable of explaining the observed mass loss as a stellar wind from a hot corona. The method gives a stationary solution to the coupled equations of motion, continuity and energy balance. The equation of motion contains
A. G. Hearn, I. M. Vardavas
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Observations of stellar coronae [PDF]
Symposium - International Astronomical Union, 1987 We present an overview of recent stellar X-ray observations, with some discussion of the requirements for future observations. We argue that solar observations indicate that coronal X-ray emission is strongly related to surface magnetic field activity; we show that the interpretation of X-ray stellar coronal emission from late-type stars within the ...
G. S. Vaiana, S. Sciortino
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