Results 231 to 240 of about 276 (256)
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2005
This paper reviews our present understanding of coronal heating, structuring and variability that has emerged from space observations of the Sun and nearby stars. It is shown that a basic analogy exists between solar coronal physics and the phenomena observed in the coronae of other late-type stars.
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This paper reviews our present understanding of coronal heating, structuring and variability that has emerged from space observations of the Sun and nearby stars. It is shown that a basic analogy exists between solar coronal physics and the phenomena observed in the coronae of other late-type stars.
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Energy release in stellar coronae
Advances in Space Research, 2003Abstract Stellar coronae pose a number of fundamental problems with regard to their high temperatures, their production of high-energy particles, and their stability against several energy loss mechanisms. The solution to most of these problems is Likely to be found in the ubiquitous coronal magnetic fields that release the required energy ...
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Stellar Chromospheres, Coronae, and Winds
1992Chromospheres, 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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1992
The one great point of similarity between the coronae of hot and cool stars is that both are spatially extended regions of more-or-less tenuous gas that is flowing outward, and at least some of which is at a temperature in excess of 106K. Coronae defined in this way are almost universal among stars—excepting cool supergiants—but this similarity may ...
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The one great point of similarity between the coronae of hot and cool stars is that both are spatially extended regions of more-or-less tenuous gas that is flowing outward, and at least some of which is at a temperature in excess of 106K. Coronae defined in this way are almost universal among stars—excepting cool supergiants—but this similarity may ...
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X-ray coronae and stellar magnetospheres
AIP Conference Proceedings, 2010Chandra’s spectroscopic resolving power allows us to measure velocity shifts down to ∼30 km/s in line profiles. Observations covering >2Prot are needed to disentangle flaring and quiescent coronal emission. The rotational modulation in X‐ray lightcurves and spectra enable us to estimate the size and location of non‐flaring X‐ray emitting regions ...
G. A. J. Hussain +7 more
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Stellar Chromospheres, Coronae, and Winds (Invited Review)
Astrophysics and Space Science, 1986Within 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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2010
Studying the solar corona, due to its vicinity, is the starting point to understand stellar activity. The emission measure distribution vs temperature, EM(T), is a useful tool to study coronal plasmas, in fact it allows: to investigate the energy balance of coronal plasmas, to easily compare different stars, and also to compare the solar corona to that
ARGIROFFI, Costanza +3 more
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Studying the solar corona, due to its vicinity, is the starting point to understand stellar activity. The emission measure distribution vs temperature, EM(T), is a useful tool to study coronal plasmas, in fact it allows: to investigate the energy balance of coronal plasmas, to easily compare different stars, and also to compare the solar corona to that
ARGIROFFI, Costanza +3 more
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High-Energy Aspects of Stellar Coronae
Physica Scripta, 1998Sun-like stars are the sites of various high-energy processes, many of which involve a release of coronal magnetic energy. Most of our knowledge on high-energy mechanisms in stellar atmospheres (other than the Sun's) is based on observations in the radio and soft x-ray regimes. They indicate a continuous presence of MeV particles, heating to high (> 10
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Stochastic Electron Acceleration in Stellar Coronae
1985When coupled with a realistic acceleration model, the radiative signature of flare events in late-type stars is capable of giving additional, and more accurate, information concerning the nature of the accelerating regions than when the radiative signature is used alone. Here we consider the second-order Fermi, or stochastic acceleration mechanism.
T. J. Bogdan, R. Schlickeiser
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Recent VLBI Observations of Stellar Coronae
1996This paper summarizes recent (1990–1995) VLBI observations of radio emission from active stars and how they have contributed to our understanding of stellar coronae. The observational results are first summarized and then applied to three broad questions concerning the physics of stellar coronae: 1. Which radiation machanisms are responsible for
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