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Related papers: High-resolution models of solar granulation: the 2…

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Finding low-mass planets around solar-type stars requires to understand the physical variability of the host star, which greatly exceeds the planet-induced radial-velocity modulation. Different solar photospheric absorption lines have…

Solar and Stellar Astrophysics · Physics 2026-04-16 Dainis Dravins , Hans-Günter Ludwig , Matthias Steffen , Carlos Allende Prieto , Lars Koesterke

The Sun is the only star where the superficial turbulent convection can be observed at very high spatial resolution. The Solar Dynamics Observatory (SDO) has continuously observed the full Sun from space with multi-wavelength filters since…

Solar and Stellar Astrophysics · Physics 2021-08-18 J. Ballot , T. Roudier , J. M. Malherbe , Z. Frank

Realistic ab-initio 3D, radiative-hydrodynamical convection simulations of the solar granulation have been applied to FeI and FeII line formation. In contrast to classical analyses based on hydrostatic 1D model atmospheres the procedure…

Astrophysics · Physics 2007-05-23 M. Asplund , AA. Nordlund , R. Trampedach , C. Allende Prieto , R. F. Stein

Below 1 mHz, the power spectrum of helioseismic velocity measurements is dominated by the spectrum of convective motions (granulation and supergranulation) making it difficult to detect the low-order acoustic modes and the gravity modes. We…

Astrophysics · Physics 2008-10-31 S. Lefebvre , R. A. Garcia , S. J. Jimenez-Reyes , S. Turck-Chieze , S. Mathur

Supergranulation is characterized by horizontally divergent flows with typical length scales of 32 Mm in the solar photosphere. Unlike granulation, the size of which is comparable to both the thickness of the radiative boundary layer and…

Solar and Stellar Astrophysics · Physics 2016-10-05 Jean-Francois Cossette , Mark Peter Rast

Three-dimensional numerical simulations of solar surface magnetoconvection using realistic model physics are conducted. The thermal structure of convective motions into the upper radiative layers of the photosphere, the main scales of…

Solar and Stellar Astrophysics · Physics 2015-05-13 Sergey D. Ustyugov

High-resolution images of the solar surface show a granulation pattern of hot rising and cooler downward-sinking material -- the top of the deep-reaching solar convection zone. Convection plays a role for the thermal structure of the solar…

Solar and Stellar Astrophysics · Physics 2011-12-14 Bernd Freytag , Matthias Steffen , Hans-Günter Ludwig , Sven Wedemeyer-Böhm , Werner Schaffenberger , Oskar Steiner

Solar granules are bright patterns surrounded by dark channels called intergranular lanes in the solar photosphere and are a manifestation of overshooting convection. Observational studies generally find stronger upflows in granules and…

Solar and Stellar Astrophysics · Physics 2017-11-01 T. Oba , T. L. Riethmüller , S. K. Solanki , Y. Iida , C. Quintero Noda , T. Shimizu

Gas convection is observed in the solar photosphere as the granulation, i.e., having highly time-dependent cellular patterns, consisting of numerous bright cells called granules and dark surrounding-channels called intergranular lanes. Many…

Solar and Stellar Astrophysics · Physics 2020-03-04 T. Oba , Y. Iida , T. Shimizu

Surface granulation of the Sun is primarily a consequence of thermal transport in the outer 1 % of the radius. Its typical scale of about 1 - 2 Mm is set by the balance between convection, free-streaming radiation, and the strong density…

Solar and Stellar Astrophysics · Physics 2015-06-18 Shravan M. Hanasoge , Katepalli R. Sreenivasan

The granulation background seen in the power spectrum of a solar-like oscillator poses a serious challenge for extracting precise and detailed information about the stellar oscillations. Using a 3D hydrodynamical simulation of the Sun…

Solar and Stellar Astrophysics · Physics 2020-12-02 Mia S. Lundkvist , Hans-Günter Ludwig , Remo Collet , Thomas Straus

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Carlos Rijs , Hamed Moradi , Damien Przybylski , Paul S. Cally

Below the scale of supergranules we find that cellular flows are present in the solar photosphere at two distinct size scales, approximately 2 Mm and 4 Mm, with distinct characteristic times. Simultaneously present in the flow is a…

Astrophysics · Physics 2015-06-24 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin

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

A 3D simulation of the upper part of the solar convective zone is used to derive constraints about the averaged and dynamic properties of solar turbulent convection. Theses constraints are then used to compute the acoustic energy supply…

Astrophysics · Physics 2007-05-23 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

Recent progress in realistic simulations of solar convection have given us an unprecedented opportunity to evaluate the robustness of solar interior structures and dynamics obtained by methods of local helioseismology. We present results of…

Supergranulation is a fluid-dynamical phenomenon taking place in the solar photosphere, primarily detected in the form of a vigorous cellular flow pattern with a typical horizontal scale of approximately 30--35~megameters, a dynamical…

Solar and Stellar Astrophysics · Physics 2018-07-05 Francois Rincon , Michel Rieutord

We examine the role of small-scale granulation in helping to drive supergranulation and even larger scales of convection. The granulation is modeled as localized cooling events introduced at the upper boundary of a 3-D simulation of…

Solar and Stellar Astrophysics · Physics 2012-01-24 Neal Hurlburt , Marc DeRosa , Kyle Augustson , Juri Toomre

Stellar surface magnetoconvection (granulation) creates asymmetries in the observed stellar absorption lines that can subsequently manifest themselves as spurious radial velocities shifts. In turn, this can then mask the Doppler-reflex…

Earth and Planetary Astrophysics · Physics 2019-07-10 H. M. Cegla , C. A. Watson , S. Shelyag , M. Mathioudakis , S. Moutari

A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity that it has been obtained by inverting spectro-polarimetric observations, rather…

Solar and Stellar Astrophysics · Physics 2015-05-27 H. Socas-Navarro