Results 51 to 60 of about 429,319 (205)

Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP

Nature Communications, 2022
Cosmogenic radionuclides from ice cores and tree rings indicate that an extreme solar proton event has hit Earth about 9200 years ago. Contrary to expectations, the event occurred during a quiet phase of the Sun within the 11 year solar cycle.
Chiara I. Paleari, Florian Mekhaldi, Florian Adolphi, Marcus Christl, Christof Vockenhuber, Philip Gautschi, Jürg Beer, Nicolas Brehm, Tobias Erhardt, Hans-Arno Synal, Lukas Wacker, Frank Wilhelms, Raimund Muscheler   +12 more
doaj   +1 more source

Asymmetries of the Stokes V profiles observed by HINODE SOT/SP in the quiet Sun

, 2011
We present the first classification of SOT/SP circular polarization measurements with the aim of highlighting exhaustively the whole variety of Stokes V shapes emerging from the quiet Sun.
Asensio Ramos, B. Viticchié, Cattaneo, Centeno, Connolly, Domínguez Cerdeña, Grossmann-Doerth, Grossmann-Doerth, Grossmann-Doerth, Ichimoto, Ishikawa, J. Sánchez Almeida, Kosugi, Lites, Louis, Martínez González, Martínez González, Neckel, Orozco Suárez, Orozco Suárez, Orozco Suárez, Orozco Suárez, Orozco Suárez, Pietari la Graham, Rees, Rees, Ruiz Cobo, Sigwarth, Skumanich, Socas-Navarro, Socas-Navarro, Solanki, Solanki, Solanki, Steiner, Stenflo, Stenflo, Sánchez Almeida, Sánchez Almeida, Sánchez Almeida, Sánchez Almeida, Sánchez Almeida, Title, Tsuneta, Viticchié, Vögler   +45 more
core   +1 more source

Ubiquitous High Speed Transition Region and Coronal Upflows in the Quiet Sun

, 2009
We study the line profiles of a range of transition region (TR) emission lines observed in typical quiet Sun regions. In magnetic network regions, the Si IV 1402\AA{}, C IV 1548\AA{}, N V 1238\AA{}, O VI 1031\AA{}, and Ne VIII 770\AA{} spectral lines ...
Bart De Pontieu, Beckers, Chae, Davey, De Pontieu, De Pontieu, De Pontieu, Fleck, Hansteen, Hara, Judge, Judge, Martínez-Sykora, McIntosh, McIntosh, McIntosh, Peter, Priest, Rouppe van der Voort, Schrijver, Scott W. McIntosh, Secchi, Tian, Tomczyk   +23 more
core   +1 more source

Ion-atom radiative processes in the solar atmosphere: quiet Sun and sunspots

, 2013
In the previous works the significance of the symmetric and non-symmetric ion-atom absorption processes in far UV and EUV regions within a model of the quiet Sun atmosphere, has been studied.
Dimitrijevic, M. S., Ignjatovic, Lj. M., Mihajlov, A. A., Sreckovic, V. A.   +3 more
core   +3 more sources

Iqsy solar eclipse, scientific expedition [PDF]

, 1965
Solar eclipse scientific observation program for International Quiet Sun Year ...

core   +1 more source

Scales of the magnetic fields in the quiet Sun [PDF]

, 2012
Context: The presence of a turbulent magnetic field in the quiet Sun has been unveiled observationally using different techniques. The magnetic field is quasi-isotropic and has field strengths weaker than 100G. It is pervasive and may host a local dynamo.
A. López Ariste, A. Sainz Dalda, Asensio Ramos, Auvergne, Carroll, Carroll, Domínguez Cerdeña, Frisch, Frisch, Frisch, Graham, Knobloch, Kosugi, Lites, López Ariste, Martínez González, Martínez González, Martínez González, Martínez Pillet, Nakagawa, Nordlund, Parker, Petrovay, Sainz Dalda, Sampoorna, Sanchez Almeida, Solanki, Solanki, Stenflo, Stenflo, Sánchez Almeida, Sánchez Almeida, Trujillo Bueno, Tsuneta, Viticchié   +34 more
core   +1 more source

On the Sr I 4607 A Hanle depolarization signals in the quiet Sun

, 2005
The Hanle depolarization signals of Sr 4607 A have been used to estimate the unsigned magnetic flux and magnetic energy existing in the quiet Sun photosphere. However, the Sr 4607 A Hanle signals are not sensitive to the unsigned flux and energy.
Almeida, J. Sanchez
core   +1 more source

On the fine structure of the quiet solar \Ca II K atmosphere [PDF]

, 2006
We investigate the morphological, dynamical, and evolutionary properties of the internetwork and network fine structure of the quiet sun at disk centre.
Schmidt, Wolfgang, Tritschler, Alexandra, Uitenbroek, Han, Wedemeyer-Boehm, Sven   +3 more
core   +2 more sources

Probing Lorentz Invariance Violation with Absorption of Astrophysical γ-Rays by Solar Photons

The Astrophysical Journal
We compute in detail the absorption optical depth for astrophysical γ -ray photons interacting with solar photons to produce electron–positron pairs. This effect is greatest for γ -ray sources at small angular distances from the Sun, reaching optical ...
Justin D. Finke, Parshad Patel
doaj   +1 more source

Fully resolved quiet-Sun magnetic flux tube observed with the Sunrise IMaX instrument

, 2010
Until today, the small size of magnetic elements in quiet Sun areas has required the application of indirect methods, such as the line-ratio technique or multi-component inversions, to infer their physical properties.
Barthol, P., Berkefeld, T., Bonet, J. A., Borrero, J. M., Domingo, V., Feller, A., Gandorfer, A., Hirzberger, J., Iniesta, J. C. del Toro, Knoelker, M., Lagg, A., Pillet, V. Martinez, Riethmueller, T. L., Schmidt, W., Schuessler, M., Solanki, S. K., Title, A. M.   +16 more
core   +1 more source