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Related papers: Probing chromospheric fine structures with a H{\al…

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We show signatures of spicules termed Rapid Blue-shifted Excursions (RBEs) in the Si iv 1394 {\AA} emission line using a semi-automated detection approach. We use the H{\alpha} filtergrams obtained by the CRISP imaging spectropolarimeter on…

Solar and Stellar Astrophysics · Physics 2022-08-17 Nived Vilangot Nhalil , Juie Shetye , J. Gerry Doyle

Filament eruptions and coronal mass ejections are physical phenomena related to magnetic flux ropes carrying electric current. A magnetic flux rope is a key structure for solar eruptions, and when it carries a southward magnetic field…

Solar and Stellar Astrophysics · Physics 2024-08-14 Brigitte Schmieder , Jinhan Guo , Stefaan Poedts

Recently, it was shown that the complex dynamical behaviour of spicules has to be interpreted as the result of simultaneous action of three kinds of motion: (1) field aligned flows, (2) swaying motions, and (3) torsional motions. We use…

Solar and Stellar Astrophysics · Physics 2013-05-07 D. H. Sekse , L. Rouppe van der Voort , B. De Pontieu , E. Scullion

Recent high-resolution observations have shown stellar winds to harbour complexities which strongly deviate from spherical symmetry, generally assumed as standard wind model. One such morphology is the archimedean spiral, generally believed…

Solar and Stellar Astrophysics · Physics 2015-07-15 Ward Homan , Leen Decin , Alex de Koter , Allard Jan van Marle , Robin Lombaert , Wouter Vlemmings

Aims. The purpose of this investigation is to characterize the temporal evolution of an emerging flux region, the associated photospheric and chromospheric flow fields, and the properties of the accompanying arch filament system. Methods.…

Solar and Stellar Astrophysics · Physics 2017-03-30 S. J. González Manrique , N. Bello González , C. Denker

Because of the complex physics that governs the formation of chromospheric lines, interpretation of solar chromospheric observations is difficult. The origin and characteristics of many chromospheric features are, because of this,…

Solar flares are caused by magnetic eruptions in active regions (ARs) on the surface of the sun. These events can have significant impacts on human activity, many of which can be mitigated with enough advance warning from good forecasts. To…

Solar and Stellar Astrophysics · Physics 2023-09-18 Varad Deshmukh , Thomas Berger , James Meiss , Elizabeth Bradley

Data-driven simulation is becoming an important approach for realistically characterizing the configuration and evolution of solar active regions, revealing the onset mechanism of solar eruption events and hopefully achieving the goal of…

Solar and Stellar Astrophysics · Physics 2023-01-25 Xinyi Wang , Chaowei Jiang , Xueshang Feng

The chromosphere of the quiet Sun is a highly intermittent and dynamic phenomenon. Three-dimensional radiation (magneto-)hydrodynamic simulations exhibit a mesh-like pattern of hot shock fronts and cool expanding post-shock regions in the…

Astrophysics · Physics 2009-11-13 Sven Wedemeyer-Böhm , Friedrich Wöger

The solar atmosphere is extremely dynamic, and many important phenomena develop on small scales that are unresolved in observations with the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO). For…

Solar and Stellar Astrophysics · Physics 2015-08-06 Irina N. Kitiashvili , Sebastien Couvidat , Andreas Lagg

Statistical properties of the Sun's photospheric turbulent magnetic field, especially those of the Active Regions (ARs), have been studied using the line-of-sight data from magnetograms taken by SOHO and several other instruments (see e.g.…

Solar and Stellar Astrophysics · Physics 2013-07-17 Shiva Kumar. Malapaka , Wolf-Christian Mueller

Solar winds originate from the Sun and can be classified as fast or slow. Fast solar winds come from coronal holes at the solar poles, while slow solar winds may originate from the equatorial region or streamers. Spicules are jet-like…

Solar and Stellar Astrophysics · Physics 2024-12-25 R. Sadeghi , E. Tavabi

Both the lack of observation of ultra-high energy (UHE) photons and the limitations of the state-of-the-art methodology being applied for their identification motivate studies on alternative approaches to the relevant simulations and the…

The highly dynamic atmosphere above sunspots exhibits a wealth of magnetohydrodynamic (MHD) waves. Recent studies suggest a coupled nature of the most prominent phenomena: umbral flashes (UFs) and running penumbral waves (RPWs). From an…

Solar and Stellar Astrophysics · Physics 2015-08-05 Johannes Löhner-Böttcher , Nazaret Bello González

Coronal Holes (CHs) are large-scale, low-density regions in the solar atmosphere which may expel high-speed solar wind streams that incite hazardous, geomagnetic storms. Coronal and solar wind models can predict these high-speed streams and…

Solar filament eruptions, flares and coronal mass ejections (CMEs) are manifestations of drastic release of energy in the magnetic field, which are related to many eruptive phenomena from the Earth magnetosphere to black hole accretion…

Solar and Stellar Astrophysics · Physics 2023-04-26 Jin-han Guo , Yi-wei Ni , Ze Zhong , Yang Guo , Chun Xia , Hai-tang Li , Stefaan Poedts , Brigitte Schmieder , Peng-fei Chen

A continuous set of echelle spectra of TW Hya, taken with the MIKE spectrograph on the Magellan2/Clay telescope at Las Campanas Observatory in April 2006 reveals systematic variations in the flux, velocity, and profile of the H-alpha…

Astrophysics · Physics 2007-05-23 A. K. Dupree , E. H. Avrett , N. S. Brickhouse , S. R. Cranmer , T. Szalai

Here we review the recent progress made in the detection, examination, characterisation and interpretation of oscillations manifesting in small-scale magnetic elements in the solar photosphere. This region of the Sun's atmosphere is…

Solar and Stellar Astrophysics · Physics 2016-03-09 David B. Jess , Gary Verth

Spicules are the most ubuiquitous type of jets in the solar atmosphere. The advent of high-resolution imaging and spectroscopy from the Interface Region Imaging Spectrograph (IRIS) and ground-based observatories has revealed the presence of…

Solar and Stellar Astrophysics · Physics 2017-11-01 Bart De Pontieu , Juan Martinez-Sykora , Georgios Chintzoglou

The Sun is the only star whose surface can be directly resolved at high resolution, and therefore constitutes an excellent test case to explore the physical origin of stellar radial-velocity (RV) variability. We present HARPS observations…

Earth and Planetary Astrophysics · Physics 2016-03-16 R. D. Haywood , A. Collier Cameron , Y. C. Unruh , C. Lovis , A. F. Lanza , J. Llama , M. Deleuil , R. Fares , M. Gillon , C. Moutou , F. Pepe , D. Pollacco , D. Queloz , D. Segransan