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Related papers: Low-degree modes

200 papers

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

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

We model the stochastic excitation of acoustic modes in solar-like pulsators taking into account the action of differential rotation. We derive the theoretical formalism for the stochastic excitation with differential rotation and make use…

Solar and Stellar Astrophysics · Physics 2024-10-31 Gabriel Biscarrat , Leïla Bessila , Stéphane Mathis

We test the relation between relative f-mode frequency variation and Lagrangian perturbation in the solar radius obtained by Dziembowski and Goode (2004) using several pairs of solar models and show that it doesn't hold true for any of the…

Astrophysics · Physics 2009-11-13 Piyali Chatterjee , H M. Antia

The helioseismic Global Oscillation at Low Frequency (GOLF) and the Variability of solar Irradiance and Gravity Oscillations (VIRGO) instruments onboard SoHO, have been observing the Sun continuously for the last 14 years. In this…

Solar and Stellar Astrophysics · Physics 2015-03-17 R. A. Garcia , D. Salabert , J. Ballot , K. Sato , S. Mathur , A. Jimenez

The observed solar p-mode velocity power spectra are compared with theoretically calculated power spectra over a range of mode degree and frequency. The shape of the theoretical power spectra depends on the depth of acoustic sources…

Astrophysics · Physics 2009-10-30 Pawan Kumar , Sarbani Basu

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

The overall framework for the study of solar convection and oscillations is the spherically symmetric component of solar structure. I discuss those properties of the solar interior which depend on convection and other possible…

Astrophysics · Physics 2016-01-27 J. Christensen-Dalsgaard

We study temporal variations in the amplitudes and widths of high-degree acoustic modes by applying the ring-diagram technique to the GONG+, MDI and HMI Dopplergrams during the declining phase of cycle 23 and rising phase of cycle 24. The…

Solar and Stellar Astrophysics · Physics 2015-06-15 Olga Burtseva , Sushant Tripathy , Richard Bogart , Kiran Jain , Rachel Howe , Frank Hill , Maria Cristina Rabello-Soares

It is expected that energetic solar flares releasing large amount of energy at the photosphere may be able to excite the acoustic ($p$-) modes of oscillations. We have determined the characteristic properties of mode parameters by applying…

Solar and Stellar Astrophysics · Physics 2014-11-20 R. A. Maurya , A. Ambastha , S. C. Tripathy

Over the past number of years, great strides have been made in identifying the various low-order magnetohydrodynamic wave modes observable in a number of magnetic structures found within the solar atmosphere. However, one aspect of these…

Context: The internal rotation of the Sun constitutes a fundamental constraint when modelling angular momentum transport in stellar interiors. In addition to the more external regions of the solar radiative zone probed by pressure modes,…

Solar and Stellar Astrophysics · Physics 2019-11-20 P. Eggenberger , G. Buldgen , S. J. A. J Salmon

Interpreting the oscillations of massive and intermediate mass stars remains a challenging task. In fast rotators, the oscillation spectrum of p-modes is a superposition of sub-spectra which correspond to different types of modes, among…

Solar and Stellar Astrophysics · Physics 2019-11-26 Benjamin Evano , François Lignières , Bertrand Georgeot

Using even-order frequency splitting coefficients of global p-modes it is possible to infer the magnetic field in the solar interior as a function of radial distance and latitude. Results obtained using GONG and MDI data are discussed.…

Astrophysics · Physics 2007-05-23 H. M. Antia

A splitting of modes in a circular graded-index optical fiber is demonstrated by solving the full Maxwell equations using the perturbation analysis. It is shown that the degeneracy of vortex Laguerre-Gauss modes with distinct orbital…

Optics · Physics 2016-04-13 Nikolai I. Petrov

Helioseismology has allowed us to infer the rotation in the greater part of the solar interior with high precision and resolution. The results show interesting conflicts with earlier theoretical expectations, indicating that the the Sun is…

Astrophysics · Physics 2007-05-23 J. Christensen-Dalsgaard , M. J. Thompson

Several works have reported changes of the Sun's subsurface stratification inferred from f-mode or p-mode observations. Recently a non-homologous variation of the subsurface layers with depth and time has been deduced from f-modes. Progress…

Astrophysics · Physics 2011-02-11 Sandrine Lefebvre , Phu Anh Phi Nghiem , Sylvaine Turck-Chieze

A Uranus orbiter would be well positioned to detect the planet's free oscillation modes, whose frequencies can resolve questions about Uranus's weakly constrained interior. We calculate the spectra that may manifest in resonances with ring…

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

Astrophysics · Physics 2009-10-31 Å. Nordlund , R. F. Stein

Solar internal rotation at high latitudes is poorly constrained by acoustic-mode helioseismology. Global inertial modes observed on the Sun are highly sensitive to solar differential rotation and may provide new diagnostics of rotation in…

Solar and Stellar Astrophysics · Physics 2026-05-20 Prithwitosh Dey , Laurent Gizon , Yuto Bekki