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The aim of this paper is to investigate whether there are any 11-yr or quasi-biennial solar cycle-related variations in solar rotational splitting frequencies of low-degree solar p modes. Although no 11-yr signals were observed, variations…

Solar and Stellar Astrophysics · Physics 2015-06-04 Anne-Marie Broomhall , David Salabert , William J. Chaplin , Rafael A. Garcia , Yvonne Elsworth , Rachel Howe , Savita Mathur

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…

We investigate the parameters of global solar p-mode oscillations, namely damping width $\Gamma$, amplitude $A$, mean squared velocity $\langle v^2\rangle$, energy $E$, and energy supply rate $\mathrm{d}E/\mathrm{d} t$, derived from two…

Solar and Stellar Astrophysics · Physics 2018-10-23 René Kiefer , Rudi Komm , Frank Hill , Anne-Marie Broomhall , Markus Roth

We have analysed the recently available GONG p-mode frequencies and splitting coefficients for a period of three and half years, including the rapidly rising phase of solar cycle 23. The analysis of mean frequency shift with different…

Astrophysics · Physics 2009-10-31 Kiran Jain , S. C. Tripathy , A. Bhatnagar

The oscillation frequencies observed in Sun-like stars are susceptible to being shifted by magnetic activity effects. The measured shifts depend on a complex relationship involving the mode type, the field strength and spatial distribution…

Solar and Stellar Astrophysics · Physics 2021-02-17 Alexandra E. L. Thomas , William J. Chaplin , Sarbani Basu , Ben Rendle , Guy Davies , Andrea Miglio

The solar interior is probed by the properties of the Sun's acoustic oscillations (p-modes) observed on the solar surface. The frequencies of these p-modes measured in the last three decades show long term variation similar to the 11 year…

Solar and Stellar Astrophysics · Physics 2026-04-23 Rekha Jain , Akash Kumar , Sushanta C. Tripathy

Observations from Parker Solar Probe's first five orbits are used to investigate the helioradial evolution of probability density functions (PDFs) of fluctuations of magnetic field components, between \(\sim 28\) - 200 \(\rs\).…

Solar and Stellar Astrophysics · Physics 2022-11-09 Rohit Chhiber

In the Sun, the properties of acoustic modes are sensitive to changes in the magnetic activity. In particular, mode frequencies are observed to increase with increasing activity level. Thanks to CoRoT and Kepler, such variations have been…

The strength and morphology of the Sun's magnetic field evolves significantly during the solar cycle, with the overall polarity of the Sun's magnetic field reversing during the maximum of solar activity. Long-term changes are also observed…

Solar and Stellar Astrophysics · Physics 2023-11-01 Adam J. Finley , Allan Sacha Brun

Characterizing the plasma state in the near-Sun environment is essential to constrain the mechanisms that heat and accelerate the solar wind. In this study, we use Parker Solar Probe (PSP) observations from Encounters 1 through 24 to…

The variations of the frequencies of the low-degree acoustic oscillations in the Sun induced by magnetic activity show a dependence with radial order. The frequency shifts are observed to increase towards higher-order modes to reach a…

Solar and Stellar Astrophysics · Physics 2018-04-04 D. Salabert , C. Régulo , F. Pérez Hernández , R. A. García

The solar magnetic activity cycle causes changes in the Sun on timescales that are relevant to human lifetimes. The minimum in solar activity that preceded the current solar cycle (cycle 24) was deeper and quieter than any other recent…

Solar and Stellar Astrophysics · Physics 2015-06-11 Sarbani Basu , Anne-Marie Broomhall , William J. Chaplin , Yvonne Elsworth

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are…

Solar and Stellar Astrophysics · Physics 2024-11-27 Rafael A. Garcia , Sylvain N. Breton , David Salabert , Sushant C. Tripathy , Kiran Jain , Savita Mathur , Eva Panetier

We investigate the behavior of the intermediate-degree mode frequencies of the sun during the current extended minimum phase to explore the time-varying conditions in the solar interior. Using contemporaneous helioseismic data from GONG and…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. C. Tripathy , K. Jain , F. Hill , J. W. Leibacher

The solar rotation profile is well constrained down to about 0.25 R thanks to the study of acoustic modes. Since the radius of the inner turning point of a resonant acoustic mode is inversely proportional to the ratio of its frequency to…

Astrophysics · Physics 2008-04-01 R. A. Garcia , S. Mathur , J. Ballot , A. Eff-Darwich , S. J. Jimenez-Reyes , S. G. Korzennik

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\nu<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data.…

Astrophysics · Physics 2009-10-31 H. M. Antia , Sarbani Basu

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

Accurate determination of the rotation rate in the radiative zone of the sun from helioseismic observations requires rotational frequency splittings of exceptional quality as well as reliable inversion techniques. We present here inferences…

Astrophysics · Physics 2009-11-13 A. Eff-Darwich , S. G. Korzennik , S. J. Jimenez-Reyes , R. A. Garcia

Measurements of the radius and limb brightening of the Sun provide important information about the solar atmosphere structure and temperature. The solar radius increases as the observation at radio frequency decreases, indicating that each…

Solar and Stellar Astrophysics · Physics 2021-12-15 Fabian Menezes , Caius L. Selhorst , Carlos Guillermo Giménez de Castro , Adriana Valio

Fossat et al. (2017) recently reported detecting rotational splitting of g modes indirectly via the interaction with p modes observed directly by the GOLF instrument on SOHO. They concluded that the core of the Sun is rotating 3:8 ? 0:1…

Solar and Stellar Astrophysics · Physics 2019-05-29 P. H. Scherrer , D. O. Gough