On the sizes of stellar X-ray coronae

@article{Ness2004OnTS,
  title={On the sizes of stellar X-ray coronae},
  author={J.‐U. Ness and Manuel Gudel and Juergen H.M.M. Schmitt and M. Audard and Alessandra Telleschi},
  journal={Astronomy and Astrophysics},
  year={2004},
  volume={427},
  pages={667-683}
}
Spatial information from stellar X-ray coronae cannot be assessed directly, but scaling laws from the solar corona make it possible to estimate sizes of stellar coronae from the physical parameters temperature and density. While coronal plasma temperatures have long been available, we concentrate on the newly available density measurements from line fluxes of X-ray lines measured for a large sample of stellar coronae with the Chandra and XMM-Newton gratings. We compiled a set of 64 grating… Expand
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  • P. Testa
  • Physics, Medicine
  • Proceedings of the National Academy of Sciences
  • 2010
TLDR
The progress made in the study of high energy stellar physics and its impact in a wider astrophysical context is discussed, focusing on the role of spectral diagnostics now accessible. Expand
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References

SHOWING 1-10 OF 41 REFERENCES
A Spectroscopic Measurement of the Coronal Density of Procyon
TLDR
A direct spectroscopic measurement of the coronal density was obtained for the star Procyon with the spectrometer on board the Extreme Ultraviolet Explorer satellite, and it is estimated that ∼6 percent of the stellar surface is covered with ∼7 x 104 coronal loops. Expand
Are stellar coronae optically thin in X-rays?. A systematic investigation of opacity effects
The relevance of resonant scattering in the solar corona has always been discussed controversially. Ratios of emission lines from identical ions but different oscillator strengths have been used inExpand
The XMM-Newton View of Stellar Coronae: High-Resolution X-Ray Spectroscopy of Capella
We present the high-resolution RGS X-ray spectrum of the stellar binary Capella observed by the XMM- Newton satellite. A multi-thermal approach has rst been applied to t the data and derive elementalExpand
The X-Ray Sun in Time: A Study of the Long-Term Evolution of Coronae of Solar-Type Stars
We have used the ASCA and ROSAT X-ray satellites to probe the coronae of a sample of nine solar-like G stars. These stars are all ostensibly single with ages ranging from 70 Myr to 9 Gyr and haveExpand
Tomography of a stellar X-ray corona: alpha Coronae Borealis
We interpret the X-ray light curve obtained by XMM-Newton during a total X-ray eclipse in the nearby binary star α Coronae Borealis. This system consists of a G5 V main-sequence star orbiting anExpand
Coronal abundances from high-resolution X-ray data: The case of Algol
We discuss the determination of elemental abundances from high resolution X-ray data. We emphasize the need for an accurate determination of the underlying temperature structure and advocate the useExpand
X-ray emission from a metal depleted accretion shock onto the classical T Tauri star TW Hya
We present the X-ray spectrum of TW Hya observed at high and intermediate spectral resolution with the Reflection Grating Spectrometer (RGS) and the European Photon Imaging Camera (EPIC) onboard theExpand
Modeling the Ne IX Triplet Spectral Region of Capella with the Chandra and XMM-Newton Gratings
High-resolution X-ray spectroscopy with the diffraction gratings of Chandra and XMM-Newton offers new chances to study a large variety of stellar coronal phenomena. A popular X-ray calibration targetExpand
CHANDRA-LETGS X-ray observations of Capella. Temperature, density and abundance diagnostics
We report an analysis of the X-ray spectrum of Capella from 6 to 175 Å obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board of the X-ray space observatory CHANDRA. ManyExpand
The Structure of Stellar Coronae in Active Binary Systems
A survey of 28 stars (22 active binary systems, plus six single stars or wide binaries for comparison) using extreme ultraviolet spectra has been conducted to establish the structure of stellarExpand
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