Results 11 to 20 of about 3,957 (226)

Alfvén Wave Connection between the Chromosphere and the Corona of the Sun: An Analytical Study

open access: yesThe Astrophysical Journal, 2023
Alfvén waves are closely relevant to the three outstanding problems in the solar corona: coronal heating, solar wind acceleration, and the fractionization of low first ionization potential (FIP) elements.
Jongchul Chae, Kyoung-Sun Lee
doaj   +2 more sources

Why “Solar Tsunamis” Rarely Leave Their Imprints in the Chromosphere

open access: yesThe Astrophysical Journal Letters, 2023
Solar coronal waves frequently appear as bright disturbances that propagate globally from the eruption center in the solar atmosphere, just like the tsunamis in the ocean on Earth.
Ruisheng Zheng   +12 more
doaj   +2 more sources

Observing the Solar Chromosphere

open access: yes, 2007
This review is split into two parts: one on chromospheric line formation in answer to the frequent question "where is my line formed", and one presenting state-of-the-art imagery of the chromosphere. In the first part I specifically treat the formation of the Na D lines, Ca II H & K, and Halpha.
Astrophysics   +5 more
openaire   +5 more sources

How Are the Abnormally Hot Chromosphere and Corona Heated by the Solar Magnetic Fields?

open access: yesThe Astrophysical Journal
The corona is a structure possessed by stars, including the Sun. The abnormal heating of the solar corona and chromosphere is one of the greatest mysteries in modern astronomy.
K. J. Li   +5 more
doaj   +2 more sources

On the Nature of the Solar Chromosphere

open access: yes, 2006
Proceedings 23th NSO Workshop, ASP Conference Series, 354, 282, in ...
Astrophysics   +5 more
openaire   +5 more sources

A CHROMOSPHERIC CONUNDRUM? [PDF]

open access: yesThe Astrophysical Journal, 2010
We examine spectra of the Ca II H line, obtained under good seeing conditions with the VTT Echelle Spectrograph in June of 2007, and higher resolution data of the Ca II 8542 Angstrom line from Fabry-Perot instruments. The VTT targets were areas near disk center which included quiet Sun and some dispersed plage.
Judge, Philip   +3 more
openaire   +2 more sources

Review and comparison of MHD wave characteristics at the Sun and in Earth’s magnetosphere

open access: yesSolar-Terrestrial Physics, 2022
Magnetohydrodynamic (MHD) waves play a crucial role in the plasma processes of stellar atmospheres and planetary magnetospheres. Wave phenomena in both media are known to have similarities and unique traits typical of each system.
Chelpanov M. A.   +6 more
doaj   +1 more source

CAII lines in a quiet region on the Sun I. Dynamic processes in the solar atmosphere

open access: yesSolar-Terrestrial Physics, 2023
We have studied oscillation processes in the quiet Sun outside a coronal hole at different levels of the solar chromosphere. The study was based on spectroscopic observations of ionized calcium lines (K, H, and 849.8 nm) obtained by the Sayan Solar ...
Turova I. P.   +2 more
doaj   +1 more source

Structure of the Solar Atmosphere: A Radio Perspective

open access: yesFrontiers in Astronomy and Space Sciences, 2020
Solar radio emission has been providing information about the Sun for over half a century. In order to fully exploit this information, one needs to have a broader view of the solar atmosphere, which cannot be provided by radio observations alone.
Costas E. Alissandrakis
doaj   +1 more source

Dissipation of Magnetohydrodynamic Waves in the Solar Stratified Flux Tubes [PDF]

open access: yesIranian Journal of Astronomy and Astrophysics, 2023
Chromosphere is the second layer of the Sun with high variability. The increase of the temperature and the decrease of the density are observed in this layer. This unusual behavior is one of the most important problems in the solar corona.
Zahra Fazel
doaj   +1 more source

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