Results 111 to 120 of about 860 (219)

Photospheric and chromospheric activity on the young solar-type star HD 171488

, 2010
Abstract shortened. 15 pages, 7 figures, 5 tables.
Frasca, A., Biazzo, K., Kovari, Zs., Marilli, E., Cakirli, O.   +4 more
openaire   +2 more sources

MHD simulations of coronal heating

, 2015
The problem of heating the solar corona requires the conversion of magnetic energy into thermal energy. Presently, there are two promising mechanisms for heating the solar corona: wave heating and nanoflare heating.
Tam, Kuan V.
core  

Anticipating Future Flare Locations with Machine Learning and the Mg II Spectral Lines

The Astrophysical Journal
Flare precursors can indicate where and when flares occur in active regions, yet their spatial and temporal characteristics remain poorly understood.
Jonas Zbinden, Lucia Kleint
doaj   +1 more source

Slender Ca II H Fibrils Mapping Magnetic Fields in the Low Solar Chromosphere

, 2017
A dense forest of slender bright fibrils near a small solar active region is seen in high-quality narrowband Ca ii H images from the SuFI instrument onboard the Sunrise balloon-borne solar observatory.
P. Barthol, Gizon, Laurent, Rutten, Robert, S. K. Solanki, R. J. Rutten, Riethmüller, T., Riethmueller, T. L., Blanco Rodriguez, J., Knölker, M., Schmidt, W., D. Orozco Suárez, M. van Noort, M. Knölker, Martinez Pillet, V., Barthol, P., Solanki, S. K., J. Hirzberger, W. Schmidt, del Toro Iniesta, J., V. Martínez Pillet, Solanki, Parth K., Hirzberger, J., Wiegelmann, T., Szydlarski, Mikolaj Marcin, Gandorfer, A., A. Gandorfer, Orozco Suarez, D., van Noort, M., S. Jafarzadeh, Jafarzadeh, S., Solanki, S., J. Blanco Rodríguez, Pillet, V. Martinez, M. Szydlarski, T. Wiegelmann, del Toro Iniesta, J. C., Szydlarski, M., Rutten, R. J., L. Gizon, Riethmüller, T. L., J. C. del Toro Iniesta, Gizon, L., Rutten, R., Jafarzadeh, Shahin, T. L. Riethmüller, Gizon, L   +45 more
core   +1 more source

Machine Learning–based Separation of the He I 10830 Å Chromospheric Signal: Quantitative Analysis of Chromosphere–Corona Intensity in the Quiet Sun

The Astrophysical Journal Supplement Series
The He I 10830 Å line, a crucial optically thin chromospheric line, is frequently used to study coronal heating and vertical coupling across the chromosphere–corona interface.
Huaiming Li, Fangyu Xu, Yi Bi, Zhenyu Jin   +3 more
doaj   +1 more source

Velocity field of an active region filament from GRIS infrared He I and IRIS ultraviolet observations

Astronomy & Astrophysics
Context. Plasma flow measurements in solar active region filaments are rare, particularly in the infrared and ultraviolet ranges that probe the chromosphere and transition region.
Murabito M., Andretta V., Parenti S., Kuckein C., González Manrique S. J., Lezzi S. M., Guglielmino S. L.   +6 more
doaj   +1 more source

Waves, bursts, and instabilities: a multi-scale investigation of energetic plasma processes in the solar chromosphere and transition region [PDF]

, 2018
The chromosphere and transition region of the solar atmosphere provide an interface between the cool photosphere (6000 K) and the hot corona (1 million K). Both layers exhibit dramatic deviations from thermal and hydrostatic equilibrium in the form of
Madsen, Chad Allen
core  

Steady-state Heating of Diffuse Coronal Plasma in a Solar Active Region

The Astrophysical Journal
The solar corona is much hotter than lower layers of the solar atmosphere—the photosphere and chromosphere. The coronal temperature is up to 1 MK in quiet Sun areas, while up to several megakelvins in active regions, which implies a key role of the ...
Gregory D. Fleishman, Alexey A. Kuznetsov, Gelu M. Nita   +2 more
doaj   +1 more source

The propagation and damping of slow magnetoacoustic waves in the solar atmosphere

, 2012
The propagation and damping of slow magnetoacoustic waves in the solar atmosphere is investigated, with particular emphasis placed on waves with periodicities of five minutes. The basic model of a uniform temperature loop is extended by the addition of
Owen, Nicholas Robert
core  

Formation and large-scale patterns of filament channels and filaments

, 2014
2015ASSL..415..355MThe properties and large-scale patterns of filament channels and filaments are considered. Initially, the global formation locations of filament channels and filaments are discussed, along with their hemispheric pattern.
Duncan H. Mackay, Mackay, Duncan Hendry
core   +1 more source