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Related papers: Observational Searches for Solar g-modes: Some The…

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We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our…

Astrophysics · Physics 2015-06-24 R. Bruno , V. Carbone , L. Sorriso-Valvo , B. Bavassano

Short timescale flux variations are closely related to the energy release process of magnetic reconnection during solar flares. Radio light curves at 1, 2, 3.75, 9.4, and 17 GHz of 209 flares observed by the Nobeyama Radio Polarimeter from…

Solar and Stellar Astrophysics · Physics 2020-06-04 Wang Lu , Liu Si-ming , Ning Zong-jun

The direct measurements of electrons and positrons over the last 30 years, corrected for the solar effect in the force-field approximation, are considered. The resulting overall electron spectrum may be fitted with a single power law above…

Astrophysics · Physics 2011-08-19 Diego Casadei , Veronica Bindi

The existence of a turbulent small-scale solar surface dynamo is likely, considering existing numerical and laboratory experiments, as well as comparisons of a small-scale dynamo in MURaM simulations with Hinode observations. We find the…

Solar and Stellar Astrophysics · Physics 2010-03-19 Jonathan Pietarila Graham , Sanja Danilovic , Manfred Schuessler

Oscillations were observed across the whole solar disk using the Doppler shift and line depth of spectral lines from the CO molecule near 4666~nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and…

Solar and Stellar Astrophysics · Physics 2015-05-20 Matthew Penn , Tom Schad , Erin Cox

In solar-like stars, acoustic modes provide the main way of probing their internal structure and dynamics. Although these modes are expected to be ubiquitous in stars with convective envelopes, Kepler observations reveal that a significant…

Solar and Stellar Astrophysics · Physics 2026-04-30 Arthur Le Saux , Leïla Bessila , Stéphane Mathis

We explore the sensitivity of the frequencies of low-degree solar p-modes to near-surface magnetic flux on different spatial scales and strengths, specifically to active regions with strong magnetic fields and ephemeral regions with weak…

The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value,…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. Jimenez , R. A. Garcia , P. L. Palle

The phenomenon of solar "torsional oscillations" (TO) represents migratory zonal flows associated with the solar cycle. These flows are observed on the solar surface and, according to helioseismology, extend through the convection zone. We…

Solar and Stellar Astrophysics · Physics 2016-08-31 G. Guerrero , P. K. Smolarkiewicz , E. M. de Gouveia Dal Pino , A. G. Kosovichev , N. N. Mansour

There are no good predictions for the amplitudes expected from solar-like oscillations in other stars. In the absence of a definitive model for convection, which is thought to be the mechanism that excites these oscillations, the amplitudes…

Astrophysics · Physics 2011-05-05 H. Kjeldsen , T. R. Bedding

The quest for the solar gravity modes (or g modes) is key for the understanding of the structure and dynamics of the solar core. In this paper, we review the history of the solar g-mode detection which is separated in three nearly distinct…

Solar and Stellar Astrophysics · Physics 2013-09-20 T. Appourchaux , P. Pallé

A clear detection of excess of power, providing a substantial evidence for solar-like oscillations in the G5 subgiant \muher{}, is presented. This star was observed over seven nights with the SARG echelle spectrograph operating with the…

Astrophysics · Physics 2009-11-13 A. Bonanno , S. Benatti , R. Claudi , S. Desidera , R. Gratton , S. Leccia , L. Paterno'

Observational evidence for gentle chromospheric evaporation during the impulsive phase of a C9.1 solar flare is presented using data from the Reuven Ramaty High-Energy Solar Spectroscopic Imager and the Coronal Diagnostic Spectrometer on…

This paper presents the analysis of 3D evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data has been obtained from interplanetary scintillation (IPS)…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. K. Manoharan

We present statistically robust observational evidence which imposes new limits on dynamo saturation in young solar-type stars. These are inferred from the increasing amplitude of the V-band optical flux with rotation, caused by the filling…

Astrophysics · Physics 2007-05-23 Mark A. O'Dell , Peter M. Panagi , Martin A. Hendry , Andrew Collier-Cameron

The rate at which the solar wind extracts angular momentum from the Sun has been predicted by theoretical models for many decades, and yet we lack a conclusive measurement from in-situ observations. In this letter we present a new estimate…

Solar and Stellar Astrophysics · Physics 2019-11-27 Adam J. Finley , Amy L. Hewitt , Sean P. Matt , Mathew Owens , Rui F. Pinto , Victor Réville

The continuous high spatial-resolution Doppler observation of the Sun by Solar Dynamics Observatory / Helioseismic and Magnetic Imager allows us to compute helioseismic k-omega power-spectrum diagram using only oscillations inside a…

Solar and Stellar Astrophysics · Physics 2015-06-11 Junwei Zhao , Dean-Yi Chou

The dynamics of the solar wind depends intrinsically on the structure of the global solar magnetic field, which undergoes fundamental changes over the 11-yr solar cycle. For instance, the wind terminal velocity is thought to be…

Solar and Stellar Astrophysics · Physics 2017-11-29 Victor Réville , Allan Sacha Brun

Observations show that the solar p-mode frequencies change with the solar cycle. The horizontal-phase-velocity dependence of the relative frequency change, scaled by mode mass, provides depth information on the perturbation in the solar…

Astrophysics · Physics 2009-11-10 Dean-Yi Chou , Alexander Serebryanskiy

We analyze helioseismic waves near the solar equator in the presence of magnetic fields deep within the solar radiative zone. We find that reasonable magnetic fields can significantly alter the shapes of the wave profiles for helioseismic…

Astrophysics · Physics 2008-11-26 C. P. Burgess , N. S. Dzhalilov , T. I. Rashba , V. B. Semikoz , J. W. F. Valle