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Related papers: Inferring solar differential rotation through norm…

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Understanding differential rotation of Sun-like stars is of great importance for insight into the angular momentum transport in these stars. One means of gaining such information is that of asteroseismology. By a forward modeling approach…

Solar and Stellar Astrophysics · Physics 2016-02-22 Mikkel N. Lund , Mark S. Miesch , Jørgen Christensen-Dalsgaard

In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…

Astrophysics · Physics 2009-11-13 Hans Kjeldsen , Timothy R. Bedding , Joergen Christensen-Dalsgaard

Helioseismic signatures of dynamo waves have recently been discovered in variations of the solar differential rotation, offering valuable insights into the type of dynamo mechanism operating in the solar convection zone. To characterize…

Solar and Stellar Astrophysics · Physics 2025-05-19 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin , Sylvain G. Korzennik

Recently discovered inertial waves, observed on the solar surface, likely extend to the deeper layers of the Sun. Utilizing helioseismic techniques, we explore these motions, allowing us to discern inertial-mode eigenfunctions in both…

Solar and Stellar Astrophysics · Physics 2024-03-14 Krishnendu Mandal , Shravan M. Hanasoge

In this article, we derive and compute the sensitivity of measurements of coupling between normal modes of oscillation in the Sun to underlying flows. The theory is based on first-Born perturbation theory, and the analysis is carried out…

Solar and Stellar Astrophysics · Physics 2017-07-19 Shravan M. Hanasoge , Martin Woodard , H. M. Antia , Laurent Gizon , Katepalli R. Sreenivasan

Global-scale inertial modes of oscillations have been recently observed on the Sun. They might play an important dynamic and diagnostic role for the Sun. This work aims to assess the validity of simplifying assumptions in the equation of…

Solar and Stellar Astrophysics · Physics 2025-04-23 Suprabha Mukhopadhyay , Yuto Bekki , Xiaojue Zhu , Laurent Gizon

Models of solar-like oscillators yield acoustic modes at different frequencies than would be seen in actual stars possessing identical interior structure, due to modelling error near the surface. This asteroseismic "surface term" must be…

Solar and Stellar Astrophysics · Physics 2021-11-24 J. M. Joel Ong , Sarbani Basu , Mikkel N. Lund , Allyson Bieryla , Lucas S. Viani , David W. Latham

Localised modelling error in the near-surface layers of evolutionary stellar models causes the frequencies of their normal modes of oscillation to differ from those of actual stars with matching interior structures. These frequency…

Solar and Stellar Astrophysics · Physics 2021-01-13 J. M. Joel Ong , Sarbani Basu , Jean M. McKeever

Using full-disk observations obtained with the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) spacecraft, we present variations of the solar acoustic mode frequencies caused by the solar activity…

Astrophysics · Physics 2008-11-26 M. C. Rabello-Soares , S. G. Korzennik , J. Schou

Helioseismology, the study of global solar oscillations, has proved to be an extremely powerful tool for the investigation of the internal structure and dynamics of the Sun. Studies of time changes in frequency observations of solar…

Solar and Stellar Astrophysics · Physics 2023-03-15 M. P. Di Mauro

Quantitative helio- and asteroseismology require very precise measurements of the frequencies, amplitudes, and lifetimes of the global modes of stellar oscillation. It is common knowledge that the precision of these measurements depends on…

Astrophysics · Physics 2009-11-13 Thorsten Stahn , Laurent Gizon

Most helioseismic analyses are based on solar oscillations frequencies obtained by fitting symmetric peak profiles to the power spectra. However, it has now been demonstrated that the peaks are not symmetric. In this work we study the…

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

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

Recent progress in realistic simulations of solar convection have given us an unprecedented opportunity to evaluate the robustness of solar interior structures and dynamics obtained by methods of local helioseismology. We present results of…

We study the effect of localized sound-speed perturbations on global mode frequencies by applying techniques of global helioseismology on numerical simulations of the solar acoustic wave field. Extending the method of realization noise…

Astrophysics · Physics 2009-11-13 S. M. Hanasoge , T. P. Larson

The dynamics of the solar core cannot be properly constrained through the analysis of acoustic oscillation modes. Gravity modes are necessary to understand the structure and dynamics of the deepest layers of the Sun. Through recent…

Astrophysics · Physics 2009-11-13 S. Mathur , A. Eff-Darwich , R. A. García , S. Turck-Chièze

In order to make astroseismology a powerful tool to explore stellar interiors, different numerical codes should give the same oscillation frequencies for the same input physics. This work is devoted to test, compare and, if needed, optimize…

We describe and use two different statistical approaches to try and detect low-frequency solar oscillations in Sun-as-a-star data: a frequentist approach and a Bayesian approach. We have used frequentist statistics to search contemporaneous…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , T. Appourchaux , R. New

The detection of multiple mode harmonic kink oscillations in coronal loops enables to obtain information on coronal density stratification and magnetic field expansion using seismology inversion techniques. The inference is based on the…

Solar and Stellar Astrophysics · Physics 2015-06-15 I. Arregui , A. Asensio Ramos , A. J. Diaz

Inferences of sub-surface flow velocities using local domain ring-diagram helioseismology depend on measuring the frequency splittings of oscillation modes seen in acoustic power spectra. Current methods for making these measurements…

Solar and Stellar Astrophysics · Physics 2014-03-10 Benjamin J. Greer , Bradley W. Hindman , Juri Toomre