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相关论文: Simulating the outer layers of Procyon A: a compar…

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Our Sun, primarily composed of ionized hydrogen and helium, has a surface temperature of 5777~K and a radius $R_\odot \approx 696,000$ km. In the outer $R_\odot/3$, energy transport is accomplished primarily by convection. Using typical…

太阳与恒星天体物理 · 物理学 2016-01-20 Shravan Hanasoge , Laurent Gizon , Katepalli R. Sreenivasan

We show that the motions of supergranules are consistent with a model in which they are simply advected by the axisymmetric flows in the Sun's surface shear layer. We produce a 10-day series of simulated Doppler images at a 15-minute…

太阳与恒星天体物理 · 物理学 2015-05-19 David H. Hathaway , Peter E. Williams , Kevin Dela Rosa , Manfred Cuntz

The solar convection manifests as granulation and intergranulation at the solar surface. In the photosphere, convective motions induce differential Doppler shifts to spectral lines. The observed convective blueshift varies across the solar…

太阳与恒星天体物理 · 物理学 2018-03-14 Johannes Löhner-Böttcher , Wolfgang Schmidt , Franziska Stief , Tilo Steinmetz , Ronald Holzwarth

Emerging active regions are associated with convective flows on the spatial scale and lifetimes of supergranules. To understand how these flows are involved in the formation of active regions, we aim to identify where active regions emerge…

太阳与恒星天体物理 · 物理学 2024-07-17 Hannah Schunker , William Roland-Batty , Aaron C. Birch , Douglas C. Braun , Robert H. Cameron , L. Gizon

The nonlinear coupling between stellar convection and rotation is of great interest because it relates to understanding both stellar evolution and activity. We investigated the influence of rotation and the Coriolis force on the dynamics…

太阳与恒星天体物理 · 物理学 2025-02-12 Irina N. Kitiashvili , Alexander G. Kosovichev , Alan A. Wray

The outer surface layers of the sun show a clear deceleration at low latitudes. This is generally thought to be the result of a strong dominance of vertical turbulent motions associated with strong downdrafts. This strong negative radial…

天体物理学 · 物理学 2009-11-13 Axel Brandenburg

The differential rotation of the F5V-IV star Procyon A is computed for a class of models which are consistent with recent astrometric and asteroseismic data. The rotation pattern is determined by solving the Reynolds equation for motion,…

天体物理学 · 物理学 2008-11-26 A. Bonanno , M. Kueker , L. Paterno'

(abridged) Context: Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the…

太阳与恒星天体物理 · 物理学 2023-10-20 Petri J. Käpylä

We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm…

太阳与恒星天体物理 · 物理学 2015-05-14 R. F. Stein , A. Lagerfjärd , Å. Nordlund , D. Georgobiani

Spectral analysis of the spatial structure of solar subphotospheric convection is carried out for subsurface flow maps constructed using the time--distance helioseismological technique. The source data are obtained from the Helioseismic and…

太阳与恒星天体物理 · 物理学 2022-09-27 Alexander V. Getling , Alexander G. Kosovichev

We present here numerical simulations of surface solar convection which cover a box of 30$\times30\times$3.2 Mm$^3$ with a resolution of 315$\times315\times$82, which is used to investigate the dynamics of scales larger than granulation. No…

天体物理学 · 物理学 2010-11-11 M. Rieutord , H. -G. Ludwig , T. Roudier , A. Nordlund , R. Stein

Chapman's (1957) conductive model of the solar corona is characterized by a temperature varying as r**(-2/7) with heliocentric distance r. The density distribution in this non-isothermal hydrostatic model has a minimum value at 123 RS, and…

太阳与恒星天体物理 · 物理学 2015-06-05 Joseph Lemaire

We present the results of three-dimensional simulations of the deep convective envelope of a young (10 Myr) one-solar-mass star, obtained with the Anelastic Spherical Harmonic code. Since young stars are known to be faster rotators than…

天体物理学 · 物理学 2008-04-03 Jérôme Ballot , Allan Sacha Brun , Sylvaine Turck-Chièze

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…

太阳与恒星天体物理 · 物理学 2011-12-14 Bernd Freytag , Matthias Steffen , Hans-Günter Ludwig , Sven Wedemeyer-Böhm , Werner Schaffenberger , Oskar Steiner

While the velocity fluctuations of supergranulation dominate the spectrum of solar convection at the solar surface, very little is known about the fluctuations in other physical quantities like temperature or density at supergranulation…

太阳与恒星天体物理 · 物理学 2016-12-07 J. Langfellner , A. C. Birch , L. Gizon

The vectoral wind structure of daytime atmospheric boundary layer (ABL) turbulence is strongly dependent on the balance between shear-driven turbulence production of horizontal fluctuations (driven by winds at the mesoscale), and…

流体动力学 · 物理学 2018-12-10 Balaji Jayaraman , James G. Brasseur

Recent observations and theoretical studies support the theory that solar-type oscillations are intrinsically stable but excited stochastically by the turbulent convection in the outer layers of the star. The acoustic noise generated by the…

天体物理学 · 物理学 2007-05-23 Reza Samadi , Guenter Houdek

We present results of three dimensional simulations of the uppermost part of the sun, at 3 stages of its evolution. Each model includes physically realistic radiative-hydrodynamics (the Eddington approximation is used in the optically thin…

天体物理学 · 物理学 2007-05-23 F. J. Robinson , P. Demarque , S. Sofia , K. L. Chan , Y. -C. Kim , D. B. Guenther

Procyon A is a bright F5IV star in a binary system. Although the distance, mass and angular diameter of this star are all known with high precision, the exact evolutionary state is still unclear. Evolutionary tracks with different ages and…

Results of forward modelling of acoustic wave propagation in a realistic solar sub-photosphere with two cases of steady horizontal flows are presented and analysed by the means of local helioseismology. The simulations are based on fully…

天体物理学 · 物理学 2009-11-13 S. Shelyag , R. Erdelyi , M. J. Thompson