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Related papers: Velocity Fields in the Solar Photosphere

200 papers

Duo to the large magnetic Reynolds number, the magnetic helicity originating from the solar interior can be carried away through the photosphere into the corona. However, the relationship between the accumulated magnetic helicity flux…

Solar and Stellar Astrophysics · Physics 2022-04-27 Quan Wang , Shangbin Yang , Mei Zhang , Xiao Yang

Ring diagram analysis of solar oscillation power spectra obtained from MDI data is performed to study the velocity fields within the solar convection zone. The three dimensional power spectra are fitted to a model with a Lorentzian profile…

Astrophysics · Physics 2007-05-23 Sarbani Basu , H. M. Antia , S. C. Tripathy

Although the Sun's polar magnetic fields are thought to provide important clues for understanding the 11-year sunspot cycle, including the observed variations of its amplitude and period, the current database of high-quality polar-field…

Solar and Stellar Astrophysics · Physics 2013-03-05 Andrés Muñoz-Jaramillo , Neil R. Sheeley, , Jie Zhang , Edward E. DeLuca

The solar photosphere is filled by a magnetic field which is tangled on scales much smaller than the resolution capability of solar telescopes. This hidden magnetic field can be investigated via the Hanle effect. In 2007 we started a…

Solar and Stellar Astrophysics · Physics 2017-10-02 Renzo Ramelli , Michele Bianda , Svetlana Berdyugina , Luca Belluzzi , Lucia Kleint

Aims: Changes of the magnetic field and the line-of-sight velocities in the photosphere are being reported for an M-class flare that originated at a $\delta$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based…

The Solar Orbiter mission, with an orbit outside the Sun Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time, different…

Solar and Stellar Astrophysics · Physics 2021-11-24 O. Podladchikova , L. Harra , K. Barczynski , C. H. Mandrini , F. Auchere , D. Berghmans , E. Buchlin , L. Dolla , M. Mierla , S. Parenti , L. Rodriguez

The slow solar wind is generally believed to result from the interaction of open and closed coronal magnetic flux at streamers and pseudostreamers. We use 3-dimensional magnetohydrodynamic simulations to determine the detailed structure and…

Solar and Stellar Astrophysics · Physics 2022-05-11 V. Aslanyan , D. I. Pontin , A. K. Higginson , P. F. Wyper , R. B. Scott , S. K. Antiochos

In this work, we study and quantify properties of strong-field small-scale convection and compare observed properties with those predicted by numerical simulations. We analyze spectropolarimetric 630.25 nm data from a unipolar ephemeral…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Narayan , G. B. Scharmer

Estimates of the photospheric magnetic, electric and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and by using…

Solar and Stellar Astrophysics · Physics 2017-12-18 E. Lumme , J. Pomoell , E. K. J. Kilpua

The concept of surface-flux transport (SFT) is commonly used in evolving models of the large-scale solar surface magnetic field. These photospheric models are used to determine the large-scale structure of the overlying coronal magnetic…

Solar and Stellar Astrophysics · Physics 2023-04-12 Graham Barnes , Marc L. DeRosa , Shaela I. Jones , Charles N. Arge , Carl J. Henney , Mark C. M. Cheung

The results of determinations of the azimuthal and meridional velocities by time-distance helioseismology from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) from May 2010 to September 2020 at latitudes from…

Solar and Stellar Astrophysics · Physics 2021-02-26 Alexander V. Getling , Alexander G. Kosovichev , Junwei Zhao

The velocity field in the lower solar atmosphere undergoes strong interactions with magnetic fields. Many authors have pointed out that power is reduced by a factor between two and three within magnetic regions, depending on frequency,…

Solar and Stellar Astrophysics · Physics 2015-06-12 F. Giannattasio , M. Stangalini , D. Del Moro , F. Berrilli

The distribution and evolution of photospheric magnetic field in sunspots, plages and network, and variations in their relative flux content, play key roles in radial velocity (RV) fluctuations observed in Sun-as-a-star spectra.…

Solar and Stellar Astrophysics · Physics 2023-09-12 Anisha Sen , S. P. Rajaguru

Extreme precision radial-velocity spectrometers enable extreme precision stellar spectroscopy. Searches for low-mass exoplanets around solar-type stars are limited by the physical variability in stellar spectra, such as the short-term…

Solar and Stellar Astrophysics · Physics 2023-11-01 Dainis Dravins , Hans-Günter Ludwig

The properties of the solar wind, as measured in situ throughout the heliosphere, depend both on the characteristics of its coronal source and on the intrinsic processes governing its interplanetary evolution. Recently, radial and Parker…

The meridional circulation at high latitudes is crucial to the build-up and reversal of the Sun's polar magnetic fields. Here we characterize the axisymmetric flows by applying a magnetic feature cross-correlation procedure to high…

Solar and Stellar Astrophysics · Physics 2013-03-26 Lisa Rightmire-Upton , David H. Hathaway , Katie Kosak

An accurate measurement of magnetic field is very important for understanding the formation and evolution of solar magnetic fields. Currently there are two types of solar magnetic field measurement instruments: the filter-based…

Solar and Stellar Astrophysics · Physics 2023-10-10 Mei Zhang , Haocheng Zhang , Chengqing Jiang

We have derived the temporal power spectra of the horizontal velocity of the solar photosphere. The data sets for 14 quiet regions observed with the Gband filter of Hinode/SOT are analyzed to measure the temporal fluctuation of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Takuma Matsumoto , Reizaburo Kitai

Measurements of the large cellular flows on the Sun were made by local correlation tracking of supergranules seen in full-disk Doppler images obtained by the HMI instrument on the NASA SDO satellite. The hourly measurements were averaged…

Solar and Stellar Astrophysics · Physics 2021-02-24 David H. Hathaway , Lisa A. Upton

We use daily full-disk vector magnetograms from Vector Spectromagnetograph (VSM) on Synoptic Optical Long-term Investigations of the Sun (SOLIS) system to synthesize the first Carrington maps of the photospheric vector magnetic field. We…

Solar and Stellar Astrophysics · Physics 2015-06-15 S. Gosain , A. A. Pevtsov , G. V. Rudenko , S. A. Anfinogentov