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The elemental composition of the solar wind differs from the solar photospheric composition. Elements with low first ionization potential (FIP) appear enhanced compared to O in the solar wind relative to the respective photospheric…

Solar and Stellar Astrophysics · Physics 2018-11-14 Verena Heidrich-Meisner , Lars Berger , Robert F. Wimmer-Schweingruber

We use the first publically available data from the Daniel K. Inouye Solar Telescope (DKIST) to track magnetic connections from the solar photosphere into the corona. We scrutinize relationships between chromospheric magnetism and bright…

Solar and Stellar Astrophysics · Physics 2023-11-03 Philip Judge , Lucia Kleint , Roberto Casini , Alfred de Wijn , Tom Schad , Alexandra Tritschler

The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the…

We use 3D radiation magnetohydrodynamic models to investigate how the thermodynamic quantities in the simulation are encoded in observable quantities, thus exploring the diagnostic potential of the 133.5 nm lines. We find that the line core…

Solar and Stellar Astrophysics · Physics 2015-09-30 Bhavna Rathore , Mats Carlsson , Jorrit Leenaarts , Bart De Pontieu

We report on observations of highly-varying Si IV 1402.77 line profiles observed with the Interface Region Imaging Spectrograph (IRIS) during the M-class flare from 2022 January 18 at an unprecedented 0.8 s cadence. Moment analysis of this…

Solar and Stellar Astrophysics · Physics 2022-10-25 Juraj Lorincik , Vanessa Polito , Bart De Pontieu , Sijie Yu , Nabil Freij

In this study, we investigate the spatial distribution of highly varying plasma composition around one of the largest sunspots of solar cycle 24. Observations of the photosphere, chromosphere, and corona are brought together with magnetic…

Solar and Stellar Astrophysics · Physics 2021-01-27 D. Baker , M. Stangalini , G. Valori , D. H. Brooks , A. S. H. To , L. van Driel-Gesztelyi , P. Demoulin , D. Stansby , D. B. Jess , S. Jafarzadeh

This study analyzed the Doppler shift in the solar spectrum using the Interface Region Imaging Spectrograph (IRIS). Two types of oscillations were investigated: long period damp and short period damp. The researchers observed periodic…

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

The formation of the transition-region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxellian conditions characterized by a kappa-distribution exhibiting a…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jaroslav Dudík , Giulio Del Zanna , Elena Dzifčáková , Helen E. Mason , Leon Golub

The first spectroscopic observations of cool Mg II loops above the solar limb observed by NASA's Interface Region Imaging Spectrograph ({\it IRIS}; \cite{IRIS}) are presented. During the observation period IRIS is pointed off-limb allowing…

Solar and Stellar Astrophysics · Physics 2014-09-02 L. K. Harra , S. A. Matthews , D. M. Long , G. A. Doschek , B. De Pontieu

Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The…

Solar and Stellar Astrophysics · Physics 2015-02-24 G. R. Gupta , Durgesh Tripathi , Helen E. Mason

In the present work, we analyze a filament eruption associated with an ICME that arrived at L1 on August 5th, 2011. In multi-wavelength SDO/AIA images, three plasma parcels within the filament were tracked at high-cadence along the solar…

Solar and Stellar Astrophysics · Physics 2018-06-27 Manan Kocher , Enrico Landi , Susan T. Lepri

Main sequence stars of spectral types F, G, and K with low to moderate activity levels exhibit a recognizable pattern known as the first ionization potential effect (FIP effect), where elements with lower first ionization potentials are…

Solar and Stellar Astrophysics · Physics 2025-03-13 J. J. Chebly , K. Poppenhäger , J. D. Alvarado-Gómez , B. E. Wood

Solar flare electron acceleration is an efficient process, but its properties (mechanism, location) are not well constrained. Via hard X-ray (HXR) emission, we routinely observe energetic electrons at the Sun, and sometimes we detect…

Solar and Stellar Astrophysics · Physics 2023-10-09 Ross Pallister , Natasha L. S. Jeffrey

We have carried out the first comprehensive investigation of enhanced line emission from molecular hydrogen, H$_{2}$ at 1333.79 {\AA}, observed at flare ribbons in SOL2014-04-18T13:03. The cool H$_{2}$ emission is known to be fluorescently…

Solar and Stellar Astrophysics · Physics 2021-02-24 Sargam M. Mulay , Lyndsay Fletcher

Recent high-cadence flare campaigns by the Interface Region Imaging Spectrograph (IRIS) have offered new opportunities to study rapid processes characteristic of flare energy release, transport, and deposition. Here, we examine high-cadence…

Solar and Stellar Astrophysics · Physics 2025-04-16 Juraj Lörinčík , Vanessa Polito , Graham S. Kerr , Laura A. Hayes , Alexander J. B. Russell

We examine spectropolarimetric data from the CoMP instrument, acquired during the evolution of the September 10th 2017 X8.2 solar flare on the western solar limb. CoMP captured linearly polarized light from two emission lines of Fe XIII at…

Solar and Stellar Astrophysics · Physics 2019-12-25 Ryan J. French , Philip G. Judge , Sarah A. Matthews , Lidia van Driel-Gesztelyi

One of the most important features in the solar atmosphere is magnetic network and its rela- tionship with the transition region (TR), and coronal brightness. It is important to understand how energy is transported into the corona and how…

Solar and Stellar Astrophysics · Physics 2018-03-21 Ehsan Tavabi

Spectroscopic observations of prominence eruptions associated with coronal mass ejections (CMEs), although relatively rare, can provide valuable plasma and 3D geometry diagnostics. We report the first observations by the Interface Region…

The instrumental advances made in this new era of 4-meter class solar telescopes with unmatched spectropolarimetric accuracy and sensitivity, will enable the study of chromospheric magnetic fields and their dynamics with unprecedented…

Solar and Stellar Astrophysics · Physics 2021-01-20 M. Stangalini , D. Baker , G. Valori , D. B. Jess , S. Jafarzadeh , M. Murabito , A. S. H. To , D. H. Brooks , I. Ermolli , F. Giorgi , C. D. MacBride

Context: The comparison of coronal and photospheric abundances in cool stars is an essential question to resolve. In the Sun an enhancement of the elements with low first ionization potential (FIP) is observed in the corona with respect to…

Solar and Stellar Astrophysics · Physics 2009-08-12 J. Sanz-Forcada , L. Affer , G. Micela
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