Results 21 to 30 of about 269 (256)
Observations of stellar coronae and prominences [PDF]
Proceedings of the International Astronomical Union, 2013 AbstractX-ray and EUV observations of young cool stars have shown that their coronae are extremely pressured environments with temperatures and densities that are up to two orders of magnitudes larger than those observed in the solar corona. At the same time rapidly transiting absorption features in optical and UV spectra reveal the presence of large ...
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Magnetohydrostatic modelling of stellar coronae [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 We introduce to the stellar physics community a method of modelling stellar coronae that can be considered to be an extension of the potential field. In this approach, the magnetic field is coupled to the background atmosphere. The model is magnetohydrostatic (MHS) and is a balance between the Lorentz force, the pressure gradient and gravity ...
MacTaggart, David +3 more
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X-Ray Spectral Characterization of the Young Cygnus OB2 Population
The Astrophysical Journal Supplement Series, 2023 We analyze the X-ray spectra of the ∼8000 sources detected in the Cygnus OB2 Chandra Legacy Survey (this focus issue), with the goals of characterizing the coronal plasma of the young low-mass stars in the region and estimating their intrinsic X-ray ...
E. Flaccomio +9 more
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Tomography of a stellar X-ray corona:αCoronae Borealis [PDF]
Astronomy & Astrophysics, 2003 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 an X-ray dark A0 star. The secondary G star is a young, active solar analog with an age of a few 100 Myr.
Güdel, M. +3 more
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Avalanches and the Distribution of Reconnection Events in Magnetized Circumstellar Disks
The Astrophysical Journal, 2023 Cosmic rays produced by young stellar objects can potentially alter the ionization structure, heating budget, chemical composition, and accretion activity in circumstellar disks.
Marco Fatuzzo +3 more
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Predicted X-ray fluxes of stellar coronas [PDF]
Symposium - International Astronomical Union, 1970 Models of convection zones and corresponding mechanical energy fluxes were computed for 90 stellar photospheres with effective temperatures ranging from 2500 K to 41 600 K and acceleration of gravity values between 1 and 105. The most intense X-ray fluxes may be expected from stars with T ≈ 7200 K and logg ≈ 4. Detectable X-ray fluxes could be expected
C. De Loore, C. De Jager
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The Astrophysical JournalStellar coronae are believed to be the main birthplace of various stellar magnetic activities. However, the structures and properties of stellar coronae remain poorly understood. Using the Space Weather Modeling Framework with the Alfvén Wave Solar Model
Yue-Hong Chen +10 more
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Solar and stellar coronae and winds [PDF]
Proceedings of the International Astronomical Union, 2016 AbstractSolar-like stars influence their environments through their coronal emis- sion and winds. These processes are linked through the physics of the stellar magnetic field, whose strength and geometry has now been explored for a large number of stars through spectropolarimetric observations. We have now detected trends with mass and rotation rate in
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FEBS Open Bio, EarlyView.The MRP4 transporter exports several drugs and signaling molecules. Here, we identified key promoter elements regulating basal MRP4 expression. Using reporter assays, we defined a conserved region with essential Sp1 and contributory Ets sites, which controlled basal MRP4 expression.
Debora Singer +7 more
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The Solar Particle Acceleration Radiation and Kinetics (SPARK) Mission Concept
Aerospace, 2023 Particle acceleration is a fundamental process arising in many astrophysical objects, including active galactic nuclei, black holes, neutron stars, gamma-ray bursts, accretion disks, solar and stellar coronae, and planetary magnetospheres.
Hamish A. S. Reid +59 more
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