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Related papers: Macro-microturbulence in the solar photosphere

200 papers

Recently, we have developed a method useful for mapping large-scale horizontal velocity fields in the solar photosphere. The method was developed, tuned and calibrated using the synthetic data. Now, we applied the method to the series of…

Astrophysics · Physics 2009-11-13 Michal Svanda , Mirek Klvana , Michal Sobotka , Vaclav Bumba

We study the evolution of turbulence in the solar wind by solving numerically the full 3D magneto-hydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered…

Solar and Stellar Astrophysics · Physics 2015-06-22 Yue Dong , Andrea Verdini , Roland Grappin

In this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985 - 2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

Doppler shifts of the Fe I spectral line at lambda5250 Angstroms from the full solar disk obtained over the period 1986 to 2009 are analyzed to determine the circulation velocity of the solar surface along meridional planes. Simultaneous…

Solar and Stellar Astrophysics · Physics 2015-05-20 Roger K. Ulrich

The solar photosphere provides us with a laboratory for understanding turbulence in a layer where the fundamental processes of transport vary rapidly and a strongly superadiabatic region lies very closely to a subadiabatic layer. Our tools…

We derive correlation coefficients between temperature and line-of-sight velocity as a function of optical depth throughout the solar photosphere for the non-magnetic photosphere and a small area of enhanced magnetic activity. The maximum…

Astrophysics · Physics 2017-12-27 J. Koza , A. Kucera , J. Rybák , H. Wöhl

In incorporating the effect of atmospheric turbulence in the broadening of spectral lines, the so-called radial-tangential macroturbulence (RTM) model has been widely used in the field of solar-type stars, which was devised from an…

Solar and Stellar Astrophysics · Physics 2017-06-21 Yoichi Takeda , Satoru UeNo

We measure the three components of velocity dispersion, $\sigma_{R},\sigma_{\theta},\sigma_{\phi}$, for stars within 6 < R < 30 kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with…

Astrophysics of Galaxies · Physics 2015-11-11 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

Low-frequency turbulence in the solar chromosphere remains poorly understood. We address 1) the sources of low-frequency turbulence that potentially heat the chromosphere, and 2) how turbulence is transported and dissipated throughout the…

A well-known property of solar wind plasma turbulence is the observed anisotropy of the autocorrelations, or equivalently the spectra, of velocity and magnetic field fluctuations. Here we explore the related but apparently not well-studied…

It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…

Solar and Stellar Astrophysics · Physics 2015-05-14 Franck Plunian , Graeme Sarson , Rodion Stepanov

A programme to observe all A dwarfs in open clusters brighter than V=6.5 mag of various ages and in the field was initiated several years ago. In this work we present the current status of microturbulent velocity for A and F dwarfs. We have…

Solar and Stellar Astrophysics · Physics 2013-12-03 M. Gebran , R. Monier , F. Royer , A. Lobel , R. Blomme

The Sun provides us with the only spatially well-resolved astrophysical example of turbulent thermal convection. While various aspects of solar photospheric turbulence, such as granulation (one-Megameter horizontal scale), are well…

Solar and Stellar Astrophysics · Physics 2017-03-14 F. Rincon , T. Roudier , A. A. Schekochihin , M. Rieutord

Collision of the magnetic flux tubes in the Quiet Sun was proposed as one of the possible sources for the heating of the solar atmosphere (Furusawa and Sakai, 2000). The solar photosphere was observed using the New Solar Telescope ad Big…

Solar and Stellar Astrophysics · Physics 2015-05-20 Aleksandra Andic

We have obtained high resolution spectrograms of small scale magnetic structures with the Swedish 1-m Solar Telescope. We present Doppler measurements at $0\farcs{2}$ spatial resolution of bright points, ribbons and flowers and their…

Astrophysics · Physics 2008-11-26 Øystein Langangen , Mats Carlsson , Luc Rouppe van der Voort , R. F. Stein

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. This project aims at analyzing - observationally and…

Solar and Stellar Astrophysics · Physics 2025-09-24 Dainis Dravins , Hans-Günter Ludwig

The composite geometry and spectral anisotropy of the solar wind turbulence are very important topics in the investigations of solar wind. In this work, we use the magnetic field and plasma data from Wind spacecraft measured during 1995…

Space Physics · Physics 2025-05-20 Zhan Fa , H. -Q. He

Peculiar motion of the solar system, determined from the dipole anisotropy in the Cosmic Microwave Background Radiation (CMBR), has given a velocity $370$ km s$^{-1}$ along RA$=168^{\circ}$, Dec$=-7^{\circ}$. Subsequent peculiar motion…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-04 Ashok K. Singal

We have investigated the degree to which turbulence in the Very Local Interstellar Clouds resembles the highly-studied turbulence in the solar corona and the solar wind. The turbulence diagnostics for the Local Clouds are the absorption…

Astrophysics of Galaxies · Physics 2015-05-28 Steven R. Spangler , Allison H. Savage , Seth Redfield

A process of diffusion of small-scale magnetic elements inside four active regions (ARs) was analyzed. Line-of-sight magnetograms acquired by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamic Observatory (SDO) during a…

Solar and Stellar Astrophysics · Physics 2018-12-14 Valentina I. Abramenko