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Related papers: A photospheric bright point model

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Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field $B_e$, corresponding to a magnetic energy density that matches the…

Astrophysics · Physics 2009-11-13 P. J. Bushby , S. M. Houghton , M. R. E. Proctor , N. O. Weiss

Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture…

A thermodynamically consistent model for soft deformable viscoelastic magnets is formulated in actual space (Eulerian) coordinates. The possibility of a ferro-paramagnetic-type (or ferri-antiferromagnetic) transition exploiting Landau phase…

Analysis of PDEs · Mathematics 2023-02-07 Tomáš Roubíček

A comprehensive understanding of the solar magnetic cycle requires detailed modeling of the solar interior including the maintenance and variation of large scale flows (differential rotation and meridional flow), the solar dynamo and the…

Solar and Stellar Astrophysics · Physics 2010-10-29 M. Rempel

A combination of diamagnetic pumping and a nonlocal alpha-effect of the Babcock-Leighton type in a solar dynamo model helps to reproduce observations of solar magnetic activity. The period of the solar cycle can be reproduced without…

Solar and Stellar Astrophysics · Physics 2015-05-30 L. L. Kitchatinov , S. V. Olemskoy

Context. The contribution of quiet-Sun regions to the solar irradiance variability is currently unclear. Some solar-cycle variations of the quiet-Sun physical structure, such as the temperature gradient, might affect the irradiance. The…

Solar and Stellar Astrophysics · Physics 2018-09-05 M. Faurobert , M. Carbillet , L. Marquis , A. Chiavassa , G. Ricort

An exospheric kinetic solar wind model is interfaced with an observation-driven single fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the fluid approach to extrapolate the…

Solar and Stellar Astrophysics · Physics 2017-10-04 Sofia-Paraskevi Moschou , Viviane Pierrard , Rony Keppens , Jens Pomoell

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave…

Astrophysics · Physics 2011-02-11 Rebecca Centeno , Manuel Collados , Javier Trujillo Bueno

Active regions (ARs) are typical magnetic structures found in the solar atmosphere. We calculate several magnetohydrostatic (MHS) equilibrium models that include the effect of a finite plasma-$\beta$ and gravity and that are representative…

Solar and Stellar Astrophysics · Physics 2023-03-08 Jaume Terradas , Thomas Neukirch

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10x10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are…

Solar and Stellar Astrophysics · Physics 2022-04-20 Haisheng Ji , Parida Hashim , Zhenxiang Hong , Zhe Xu , Jinhua Shen , Kaifan Ji , Wenda Cao

The problem of solar chromospheric heating remains a challenging one with wider implications for stellar physics. Several studies in the recent past have shown that small-scale inclined magnetic field elements channel copious amount of…

Solar and Stellar Astrophysics · Physics 2018-12-14 S. P. Rajaguru , C. R. Sangeetha , Durgesh Tripathi

Context. High-resolution observations of the solar photosphere reveal the presence of fine structures, in particular the so-called magnetic bright points (MBPs), which are small-scale features associated with strong magnetic field regions…

Analysis of the structure and dynamics of the magnetic field of the Sun is fundamental for understanding of the origin of solar activity and variability as well as for the study of solar-terrestrial relations. Observations of the large…

Solar and Stellar Astrophysics · Physics 2018-02-21 E. A. Gavryuseva

In this paper, we show a "proof of concept" of the heating mechanism of the solar chromosphere due to wave dissipation caused by the effects of partial ionization. Numerical modeling of non-linear wave propagation in a magnetic flux tube,…

Solar and Stellar Astrophysics · Physics 2016-03-16 S. Shelyag , E. Khomenko , A. de Vicente , D. Przybylski

Coronal holes and active regions are typical magnetic structures found in the solar atmosphere. We propose several magnetohydrostatic equilibrium solutions that are representative of these structures in two dimensions. Our models include…

Solar and Stellar Astrophysics · Physics 2022-12-15 J. Terradas , R. Soler , R. Oliver , P. Antolin , I. Arregui , M. Luna , I. Piantschitsch , E. Soubrié , J. L. , Ballester

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Magnetic fields on the surface of the Sun and stars in general imprint or modify the polarization state of the electromagnetic radiation that is leaving from the star. The inference of solar/stellar magnetic fields is performed by…

Solar and Stellar Astrophysics · Physics 2016-11-23 Jaime de la Cruz Rodríguez , Michiel van Noort

The variable magnetic field of the solar photosphere exhibits periodic reversals as a result of dynamo activity occurring within the solar interior. We decompose the surface field as observed by both the Wilcox Solar Observatory and the…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. L. DeRosa , A. S. Brun , J. T. Hoeksema

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts: a lower layer where the forcing is helical and an upper…

Solar and Stellar Astrophysics · Physics 2014-10-20 Dhrubaditya Mitra , A. Brandenburg , N. Kleeorin , I. Rogachevskii

$\delta$-sunspots are known to be favourable locations for fast and energetic events like flares and CMEs. The photosphere of this type of sunspots has been thoroughly investigated in the past three decades. The atmospheric conditions in…

Solar and Stellar Astrophysics · Physics 2018-01-10 Carolina Robustini , Jorrit Leenaarts , Jaime de la Cruz Rodríguez