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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

First limits on the 3-200 keV X-ray spectrum of the quiet Sun using RHESSI [PDF]

open access: yes, 2007
We present the first results using the Reuven Ramaty High-Energy Solar Spectroscopic Imager, RHESSI, to observe solar X-ray emission not associated with active regions, sunspots or flares (the quiet Sun).
Dolan J. F.   +7 more
core   +1 more source

Quantifying Poynting Flux in the Quiet Sun Photosphere

open access: yesThe Astrophysical Journal, 2023
Poynting flux is the flux of magnetic energy, which is responsible for chromospheric and coronal heating in the solar atmosphere. It is defined as a cross product of the electric and magnetic fields, and in ideal MHD conditions it can be expressed in ...
Dennis Tilipman   +5 more
doaj   +1 more source

PRELIMINARY RESULTS OF INTERFEROMETRIC OBSERVATIONS OF THE QUIET SUN AT THE FREQUENCIES 8 – 32 MHZ

open access: yesOdessa Astronomical Publications, 2018
We studied a radio emission of the quiet Sun at decameter wavelengths to determine its angular dimensions. Observations were conducted using interferometers composed of antenna sections of the UTR-2 radio telescope.
V. A. Shepelev   +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

Vigorous convection in a sunspot granular light bridge [PDF]

open access: yes, 2014
Light bridges are the most prominent manifestation of convection in sunspots. The brightest representatives are granular light bridges composed of features that appear to be similar to granules.
Danilovic, Sanja   +3 more
core   +1 more source

Hierarchical analysis of the quiet-Sun magnetism [PDF]

open access: yesAstronomy & Astrophysics, 2014
Standard statistical analysis of the magnetic properties of the quiet Sun rely on simple histograms of quantities inferred from maximum-likelihood estimations. Because of the inherent degeneracies, either intrinsic or induced by the noise, this approach is not optimal and can lead to highly biased results.
Ramos, A. Asensio   +1 more
openaire   +2 more sources

ON THE PROPAGATION OF RADIO EMISSION IN THE CROWN OF THE QUIET SUN WITH MAGNETIC FIELD

open access: yesOdessa Astronomical Publications, 2013
There are searching for factors that influ­ence on the brightness temperature distribution of the quiet Sun at decameter radio waves which may explain the ellipsoidal shape and other features in the radio brightness profile.
N. Tsvyk
doaj   +1 more source

Formation of the Transition Region for the Quiet Sun

open access: yesThe Astrophysical Journal Letters, 2023
We propose a partially ionized collisional two-fluid model of the formation of the transition region between the cool dense chromosphere and hot tenuous corona for the quiet Sun.
Paul Song, Jiannan Tu, David B. Wexler
doaj   +1 more source

The quiet sun at mm wavelengths as seen by ALMA

open access: yesFrontiers in Astronomy and Space Sciences, 2022
Solar observations at sub-mm, mm and cm wavelengths offer a straightforward diagnostic of physical conditions in the solar atmosphere because they yield measurement of brightness temperature which, for optically thick features, equals intrinsic ...
Costas E. Alissandrakis   +2 more
doaj   +1 more source

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