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Related papers: On the formation of solar wind & switchbacks, and …

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The Mg II h&k lines are amongst the best diagnostic tools of the upper solar chromosphere. This region of the atmosphere is of particular interest as it is the lowest region of the Sun's atmosphere where the magnetic field is dominant in…

Solar and Stellar Astrophysics · Physics 2023-03-01 Viggo Hansteen , Juan Martinez Sykora , Mats Carlsson , Bart De Pontieu , Milan Gosic , Souvik Bose

Upflows at the edges of active regions (ARs) are studied by spatially and temporally combining multi-instrument observations obtained with EIS/Hinode, AIA and HMI/SDO and IBIS/NSO, to derive their plasma parameters. This information is used…

Solar and Stellar Astrophysics · Physics 2015-11-18 K. Vanninathan , M. S. Madjarska , K. Galsgaard , Z. Huang , J. G. Doyle

Active region (AR) outflows have been studied in detail since the launch of \textit{Hinode}/EIS and are believed to provide a possible source of mass and energy to the slow solar wind. In this work, we investigate the lower atmospheric…

Solar and Stellar Astrophysics · Physics 2020-11-11 Vanessa Polito , Bart De Pontieu , Paola Testa , David H. Brooks , Viggo Hansteen

The strength and morphology of the Sun's magnetic field evolves significantly during the solar cycle, with the overall polarity of the Sun's magnetic field reversing during the maximum of solar activity. Long-term changes are also observed…

Solar and Stellar Astrophysics · Physics 2023-11-01 Adam J. Finley , Allan Sacha Brun

Small-scale transient phenomena in the quiet Sun are believed to play an important role in coronal heating and solar wind generation. One of them named as "X-ray jet" is the subject of our study. We indent to investigate the dynamics,…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. S. Madjarska

The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. Peter , S. Bingert

Studying the emergence of magnetic fields is essential for understanding the physical mechanisms behind various phenomena in the solar atmosphere. Most importantly, the emerging fields offer valuable insights into how energy and mass are…

Solar and Stellar Astrophysics · Physics 2025-08-28 Milan Gošić , Viggo H. Hansteen , Alberto Sainz Dalda , Bart De Pontieu , Luc H. M. Rouppe van der Voort

We need to establish a correspondence between the magnetic structures generated by models and usual stellar activity indexes to simulate radial velocity time series for stars less active than the Sun. This is necessary to compare the…

Solar and Stellar Astrophysics · Physics 2018-08-01 Nadège Meunier

The Sun's outer atmosphere, the corona, is maintained at mega-Kelvin temperatures and fills the heliosphere with a supersonic outflowing wind. The dissipation of magnetic waves and direct electric currents are likely to be the most…

Solar and Stellar Astrophysics · Physics 2025-03-21 A. K. Srivastava , Sripan Mondal , Eric R. Priest , Sudheer K. Mishra , David I. Pontin , R. Y. Kwon , Ding Yuan , K. Murawski , Ayumi Asai

Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun and the outer layers. We…

Solar and Stellar Astrophysics · Physics 2021-03-05 T. Roudier , M. Švanda , J. M. Malherbe , J. Ballot , D. Korda , Z. Frank

Wave theories of heating the chromosphere, corona, and solar wind due to photospheric fluctuations are strengthened by the existence of observed wave coherency up to the transition region (TR). The coherency of solar spicules' intensity…

Solar and Stellar Astrophysics · Physics 2017-02-08 Alireza Ahangarzadeh Maralani , Ehsan Tavabi , Ali Ajabshirizadeh

We investigate the evolution of interplanetary coronal mass ejection (ICME) sheath regions at 1 AU across solar cycles 23, 24, and the rising phase of 25, focusing on their variability and turbulence in relation to upstream solar wind…

Solar and Stellar Astrophysics · Physics 2026-01-14 C. Larrodera , M. Temmer , M. Owens

The heating of the chromosphere in internetwork regions remains one of the foremost open questions in solar physics. In the present study we tackle this old problem by using a very high spatial-resolution simulation of quiet-Sun conditions…

Aims: To study the heating of solar chromospheric magnetic and nonmagnetic regions by acoustic and magnetoacoustic waves, the deposited acoustic-energy flux derived from observations of strong chromospheric lines is compared with the total…

Solar and Stellar Astrophysics · Physics 2021-04-07 V. Abbasvand , M. Sobotka , M. Švanda , P. Heinzel , W. Liu , L. Mravcová

Connecting in-situ measured solar-wind plasma properties with typical regions on the Sun can provide an effective constraint and test to various solar wind models. We examine the statistical characteristics of the solar wind with an origin…

Solar and Stellar Astrophysics · Physics 2017-02-22 Hui Fu , Maria S. Madjarska , Lidong Xia , Bo Li , Zhenghua Huang , Zhipeng Wangguan

Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare observed on 2011 February 16 07:44…

Solar and Stellar Astrophysics · Physics 2015-06-12 Peter Young , George Doschek , Harry Warren , Hiro Hara

Two of the most important features of the solar atmosphere are its hot, smooth coronal loops and the concentrations of magnetic shear, known as filament channels, that reside above photospheric polarity inversion lines (PILs). The shear…

Solar and Stellar Astrophysics · Physics 2016-06-30 Kalman J. Knizhnik

Coronal loops interconnecting two active regions, called as interconnecting loops (ILs), are prominent large-scale structures in the solar atmosphere. They carry a significant amount of magnetic flux, therefore are considered to be an…

Solar and Stellar Astrophysics · Physics 2018-06-27 Guohui Du , Yao Chen , Chunming Zhu , Chang Liu , Lili Ge , Bing Wang , Chuanyang Li , Haimin Wang

The solar chromosphere is a transition layer between the cool, dense photosphere and the hot, rarefied corona. This boundary region plays a key role in regulating energy transport and structuring the magnetic field throughout the solar…

Solar and Stellar Astrophysics · Physics 2026-04-14 M. Kriginsky , J. Leenaarts , J. de la Cruz Rodriguez , S. Danilovic , O. Andriienko

The connection between nuclear fusion in the Sun's core and solar irradiance is obscured among other things by uncertainty over the mechanism of coronal heating. Data for solar wind density and velocity, sunspot number, and EUV flux suggest…

Solar and Stellar Astrophysics · Physics 2016-09-16 Claudio Vita-Finzi