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Related papers: Solar velocity references from 3D HD photospheric …

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The goal of this paper is to investigate Reynolds stresses and to check if it is plausible that they are responsible for angular momentum transfer toward the solar equator. We also analysed meridional velocity, rotation velocity residuals…

Solar and Stellar Astrophysics · Physics 2014-03-05 D. Sudar , I. Skokić , D. Ruždjak , R. Brajša , H. Wöhl

We establish a quantitative relationship between photometric and spectroscopic detections of solar-like oscillations using ab initio, three-dimensional (3D), hydrodynamical numerical simulations of stellar atmospheres. We present a…

Solar and Stellar Astrophysics · Physics 2021-02-17 Yixiao Zhou , Thomas Nordlander , Luca Casagrande , Meridith Joyce , Yaguang Li , Anish M. Amarsi , Henrique Reggiani , Martin Asplund

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway , Thibaud Teil , Aimee A. Norton , Irina Kitiashvili

For hydrodynamic model atmospheres, absolute lineshifts are becoming an observable diagnostic tool beyond the classical ones of line-strength, -width, -shape, and -asymmetry. This is the wavelength displacement of different types of…

Astrophysics · Physics 2007-05-23 Dainis Dravins

The observed solar photospheric magnetic fields and Doppler velocities are frequently used to quantify the Poynting flux and helicity flux. Multiple methods have been developed for this purpose, but their estimates of the Poynting flux and…

Solar and Stellar Astrophysics · Physics 2026-04-20 Jiayi Liu , Xudong Sun , Peter W. Schuck , Lars K. S. Daldorff

We reanalyse the measurements of parallax, proper motion, and line-of-sight velocity for 18 masers in high mass star-forming regions presented by Reid et al. (2009). We use a likelihood analysis to investigate the distance of the Sun from…

Astrophysics of Galaxies · Physics 2015-05-13 Paul J. McMillan , James J. Binney

A new method of measurement of the velocities of solar electron antineutrinos is proposed. The method is based on the assumption, that if the neutrino detector having a shape of a pipe and providing a proper angular resolution, is directed…

Nuclear Theory · Physics 2007-05-23 Elmir Dermendjiev

We use about 200,000 FGK type main-sequence stars from the LAMOST DR1 data to map the local stellar kinematics. With the velocity de-projection technique, we are able to derive the averaged 3 dimensional velocity and velocity ellipsoids…

Astrophysics of Galaxies · Physics 2017-12-06 Hai-Jun Tian , Chao Liu , Jeffrey L. Carlin , Yong-Heng Zhao , Xue-Lei Chen , Yue Wu , Guang-Wei Li , Yong-Hui Hou , Yong Zhang

Recently, new solar model atmospheres have been developed to replace classical 1D LTE hydrostatic models and used to for example derive the solar chemical composition. We aim to test various models against key observational constraints. In…

Solar and Stellar Astrophysics · Physics 2015-06-15 Tiago M. D. Pereira , Martin Asplund , Remo Collet , Irina Thaler , Regner Trampedach , Jorrit Leenaarts

Observations of the dynamics of solar coronal structures are necessary to investigate space weather phenomena and global heating of the corona. The profiles of high temperature lines emitted by the hot plasma are usually integrated by…

Solar and Stellar Astrophysics · Physics 2021-10-27 J. -M. Malherbe , P. Mein , F. Sayede , P. Rudawy , K. Phillips , F. Keenan , J. Rybak

We present a comprehensive study of one method for measuring various parameters of global modes of oscillation of the Sun. Using velocity data taken by the Michelson Doppler Imager (MDI), we analyze spherical harmonic degrees l <= 300. Both…

Solar and Stellar Astrophysics · Physics 2015-11-18 Tim Larson , Jesper Schou

Time-distance helioseismology provides information about vector flows in the near-surface layers of the Sun by measuring wave travel times between points on the solar surface. Specific spatial averages of travel times have been proposed for…

Solar and Stellar Astrophysics · Physics 2015-01-05 Jan Langfellner , Laurent Gizon , Aaron C. Birch

A method to measure the seeing from video made during drift-scan solar transits is proposed. The limb of the Sun is projected over a regular grid evenly spaced. The temporal dispersion of the time intervals among the contacts between solar…

Instrumentation and Methods for Astrophysics · Physics 2011-06-14 Costantino Sigismondi

Full-disk observations from missions such as the SDO and SOHO have enabled comprehensive studies of solar oscillations and dynamics. Interpreting helioseismic and photospheric data is complicated by systematic center-to-limb variations. To…

Solar and Stellar Astrophysics · Physics 2026-04-06 Irina N. Kitiashvili

In a previous paper, I described a new way of determining the high-latitude solar rotation rate statistically from space-time maps of polar faculae observed in the 6767 \r{A} continuum by the Michelson Doppler Interferometer (MDI) on the…

Solar and Stellar Astrophysics · Physics 2025-02-04 Neil R. Sheeley

Using data collected by the Indian Mars Orbiter Mission in October 2021, we investigated coronal regions of the Sun by analyzing the Doppler spectral width of radio signals to estimate solar wind velocity. A simplified equation is…

Solar and Stellar Astrophysics · Physics 2025-04-02 Keshav Aggarwal , R. K. Choudhary , Abhirup Datta , Roopa M. V. , Bijoy K. Dai

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

Solar and Stellar Astrophysics · Physics 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

We re-estimate the peculiar velocity of the Sun with respect to the local standard of rest using a sample of local stars within 600 pc of the Sun, selected from the LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC). The…

Astrophysics of Galaxies · Physics 2015-06-23 Yang Huang , Xiaowei Liu , Haibo Yuan , Maosheng Xiang , Zhiying Huo , Bingqiu Chen , Yong Zhang , Yonghui Hou

We have analysed the asymmetry of lines Fe I and Fe II in spectra of a solar flux using three FTS atlases and the HARPS atlas and also in spectra of 13 stars using observation data on the HARPS spectrograph. To reduce observation noise…

Solar and Stellar Astrophysics · Physics 2021-03-31 V. A. Sheminova

Helioseismic inferences of large-scale flows in the solar interior necessitate accounting for the curvature of the Sun, both in interpreting systematic trends introduced in measurements as well as the sensitivity kernel that relates…

Solar and Stellar Astrophysics · Physics 2020-12-23 Jishnu Bhattacharya
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