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Related papers: Recent results in Ring Diagram analysis

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Context. Far-side helioseismology is a technique used to infer the presence of active regions in the far hemisphere of the Sun based on the interpretation of oscillations measured in the near hemisphere. A neural network has been recently…

Solar and Stellar Astrophysics · Physics 2021-08-25 E. G. Broock , T. Felipe , A. Asensio Ramos

Solar filament oscillations have been known for decades. Now thanks to the new capabilities of the new telescopes, these periodic motions are routinely observed. Oscillations in filaments show key aspects of their structure. A systematic…

Solar and Stellar Astrophysics · Physics 2022-10-26 Manuel Luna , Joan-René Merou Mestre , Frédéric Auchère

Redshifted 21 cm radiation originating from the cosmological distribution of neutral hydrogen (HI) appears as a background radiation in low frequency radio observations. The angular and frequency domain fluctuations in this radiation carry…

Astrophysics · Physics 2007-05-23 Somnath Bharadwaj , SK. Saiyad Ali

Previous studies have used magnetic energy and helicity spectra, the latter computed using the two-scale method, to search for signatures of mean-field dynamos. In this study, we compare cotemporal HMI and SOLIS magnetograms to illustrate…

Solar and Stellar Astrophysics · Physics 2025-05-02 G. Kishore , Nishant K. Singh

We analyze the effect of a sunspot in its quiet surroundings applying a helioseismic technique on almost three years of Helioseismic and Magnetic Imager (HMI) observations obtained during solar cycle 24 to further study the sunspot…

Solar and Stellar Astrophysics · Physics 2018-05-23 M. Cristina Rabello-Soares , Richard S. Bogart , Philip H. Scherrer

The questions whether the Sun shrinks with the solar activity and what causes this have been a subject of debate. Helioseismology provides means to measure with high precision the radial displacement of subsurface layers, co-called "seismic…

Solar and Stellar Astrophysics · Physics 2018-07-25 Alexander Kosovichev , Jean-Pierre Rozelot

Context. We present the first high-cadence multi-wavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar \'echelle spectrograph at the Hertzsprung SONG Telescope operating at…

Three types of observations: the daily values of the solar radio flux at 7 frequencies, the daily international sunspot number and the daily Stanford mean solar magnetic field were processed in order to find all the periodicities hidden in…

Astrophysics · Physics 2009-11-07 S. Zieba , J. Maslowski , A. Michalec , A. Kulak

We discuss how recent advances in observations, theory and numerical simulations have allowed the stellar community to progress in its understanding of stellar convection, rotation and magnetism and to assess the degree to which the Sun and…

Solar and Stellar Astrophysics · Physics 2015-03-24 A. S. Brun , R. A. Garcia , G. Houdek , D. Nandy , M. Pinsonneault

This article presents a power-spectrum analysis of 39,024 measurements of the solar diameter made at the Mount Wilson Observatory from 1968.670 to 1997.965. This power spectrum contains a number of very strong peaks. We find that eight of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Peter A. Sturrock , Luca Bertello

We present an adaptation of the rotation-corrected, m-averaged spectrum technique designed to observe low signal-to-noise-ratio, low-frequency solar p modes. The frequency shift of each of the 2l+1 m spectra of a given (n,l) multiplet is…

Solar and Stellar Astrophysics · Physics 2011-02-11 D. Salabert , J. Leibacher , T. Appourchaux , F. Hill

We present the assessment of a diffusion-dominated mean field axisymmetric dynamo model in reproducing historical solar activity and forecast for solar cycle 25. Previous studies point to the Sun's polar magnetic field as an important proxy…

Solar and Stellar Astrophysics · Physics 2018-06-29 Alejandro Macario-Rojas , Katharine L. Smith , Peter C. E. Roberts

Using high-resolution ring analysis (HRRA) we deduce subsurface flows within magnetic active regions and within quiet sun. With this procedure we are capable of measuring flows with a horizontal spatial resolution of 2 degrees in…

Solar and Stellar Astrophysics · Physics 2011-02-11 Bradley W. Hindman , Deborah A. Haber , Juri Toomre

In our previous articles (Chertok et al.: 2013, Solar Phys. 282, 175, and 2015, Solar Phys. 290, 627), we presented a preliminary tool for the early diagnostics of the geoeffectiveness of solar eruptions based on the estimate of the total…

Solar and Stellar Astrophysics · Physics 2017-04-19 I. M. Chertok , V. V. Grechnev , A. A. Abunin

Here we review the recent progress made in the detection, examination, characterisation and interpretation of oscillations manifesting in small-scale magnetic elements in the solar photosphere. This region of the Sun's atmosphere is…

Solar and Stellar Astrophysics · Physics 2016-03-09 David B. Jess , Gary Verth

Almost 100 years ago Sir Arthur Eddington noted that the interiors of stars were inaccessible to observations. The advent of helio- and asteroseismology has completely changed this assessment. Helioseismology has provided very detailed…

Solar and Stellar Astrophysics · Physics 2016-02-23 J. Christensen-Dalsgaard

It is now well established that the quiet Sun contains in total more magnetic flux than active regions and represents an important reservoir of magnetic energy. But the nature and evolution of these fields remain largely unknown. We…

Solar and Stellar Astrophysics · Physics 2021-07-07 Marianne Faurobert , Gilbert Ricort

Context: Studying the motions on the solar surface is fundamental for understanding how turbulent convection transports energy and how magnetic fields are distributed across the solar surface. Aims: From horizontal velocity measurements all…

Solar and Stellar Astrophysics · Physics 2015-06-22 Th. Roudier , M. Švanda , M. Rieutord , J. M. Malherbe , R. Burston , L. Gizon

The Sun's magnetic field is strongly structured over a broad range of scales. The magnetic spatial power spectral analysis provides a powerful tool to understand the various scales of magnetic fields and their interaction with plasma…

Solar and Stellar Astrophysics · Physics 2023-08-16 Yukun Luo , Jie Jiang , Ruihui Wang

Today's picture of the internal solar rotation rate profile results essentially from helioseismic analyses of frequency splittings of resonant acoustic waves. Here we present another, complementary estimation of the internal solar rotation…

Solar and Stellar Astrophysics · Physics 2020-02-17 Ariane Schad , Markus Roth