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Related papers: The visibility of low-frequency solar acoustic mod…

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In order to take full advantage of the long time series collected by the GONG and MDI helioseismic projects, we present here an adaptation of the rotation-corrected $m$-averaged spectrum technique in order to observe low radial-order solar…

Astrophysics · Physics 2009-06-23 David Salabert , John W. Leibacher , Thierry Appourchaux

We investigate the spatial and temporal variations of the high-degree mode frequencies calculated over localized regions of the Sun during the extended minimum phase between solar cycles 23 and 24. The frequency shifts measured relative to…

Solar and Stellar Astrophysics · Physics 2015-06-11 S. C. Tripathy , K. Jain , Frank Hill

Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure of much of the solar interior avoiding systematic errors that…

Lateral motions of spicules serve as vital indicators of transverse waves in the solar atmosphere, and their study is crucial for understanding the wave heating process of the corona. Recent observations have focused on "high-frequency"…

Solar and Stellar Astrophysics · Physics 2023-11-29 Hidetaka Kuniyoshi , Munehito Shoda , Richard J. Morton , Takaaki Yokoyama

The possibility of detecting solar oscillation modes using space-based gravitational-wave detectors has been investigated in the context of gravitational-wave interferometry, with Polnarev \cite{Polnarev:2009xf} demonstrating that…

General Relativity and Quantum Cosmology · Physics 2026-03-25 Aman Awasthi

CoRoT and Kepler observations of red giant stars revealed very rich spectra of non-radial solar-like oscillations. Of particular interest was the detection of mixed modes that exhibit significant amplitude, both in the core and at the…

Solar and Stellar Astrophysics · Physics 2014-11-19 M. Grosjean , M. -A. Dupret , K. Belkacem , J. Montalban , R. Samadi , B. Mosser

This paper proposed a model predictive control (MPC) secondary frequency control method considering wind and solar power generation stochastics. The extended state-space matrix including unknown stochastic power disturbance is established,…

Systems and Control · Electrical Eng. & Systems 2024-09-13 Cheng Zhong , Zhifu Jiang , Xiangyu Zhang , Jikai Chen , Yang Li

We introduce a modified version of a standard power spectrum `peak-bagging' technique which is designed to gain some of the advantages that fitting the entire low-degree p-mode power spectrum simultaneously would bring, but without the…

Astrophysics · Physics 2009-11-13 S. T. Fletcher , W. J. Chaplin , Y. Elsworth , R. New

Context. Large-scale equatorial Rossby modes have been observed on the Sun over the last two solar cycles. Aims. We investigate the impact of the time-varying zonal flows on the frequencies of Rossby modes. Methods. A first-order…

Solar and Stellar Astrophysics · Physics 2020-08-05 C. R. Goddard , A. C. Birch , D. Fournier , L. Gizon

We have observed evidence for $p$-mode oscillations in the G0 IV star etaBoo (V = 2.68). This represents the first clear evidence of solar-like oscillations in a star other than the Sun. We used a new technique which measures fluctuations…

Astrophysics · Physics 2009-10-22 Hans Kjeldsen , Timothy R. Bedding , Michael Viskum , Soeren Frandsen

Being directly observed in the Doppler shift and imaging data and indirectly as quasi-periodic pulsations in solar and stellar flares, slow magnetoacoustic waves offer an important seismological tool for probing many vital parameters of the…

Solar and Stellar Astrophysics · Physics 2022-05-25 Dmitrii Y. Kolotkov , Valery M. Nakariakov

Context: Mode identification has remained a major obstacle in the interpretation of pulsation spectra in rapidly rotating stars. Aims: We would like to test mode identification methods and seismic diagnostics in rapidly rotating stars,…

Solar and Stellar Astrophysics · Physics 2017-05-24 D. R. Reese , F. Lignières , J. Ballot , M. -A. Dupret , C. Barban , C. van 't Veer-Menneret , K. B. MacGregor

Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…

Solar and Stellar Astrophysics · Physics 2023-05-31 J. Philidet , L. Gizon

Acoustic mode frequencies obtained by applying spherical harmonic decomposition to HMI, MDI and GONG observations were analysed throughout the solar cycle. Evidence of a deviation from a linear relation with solar radio flux was found…

Solar and Stellar Astrophysics · Physics 2019-04-17 M. Cristina Rabello Soares

The usual procedure for estimating the significance of a peak in a power spectrum is to calculate the probability of obtaining that value or a larger value by chance (known as the "p-value"), on the assumption that the time series contains…

High Energy Astrophysical Phenomena · Physics 2009-11-13 P. A. Sturrock , J. D. Scargle

The sense of line asymmetry of solar p-modes in the intensity power spectra is observed to be opposite of that seen in the velocity power spectra. Theoretical calculations provide a good understanding and fit to the observed velocity power…

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

In a power spectrum of the Sun's acoustic waves, the p modes have distinctly skewed frequency profiles. Furthermore, the asymmetry is observed to have the opposite sign in power spectra made from line-of-sight velocity and continuum…

Solar and Stellar Astrophysics · Physics 2011-12-21 Bradley W. Hindman

Low-m inertial modes have been recently discovered in the Sun's high-latitude regions. In this study, we characterize the observational properties of the m = 1 mode by analyzing time-distance subsurface flow maps. Synoptic flow maps,…

Solar and Stellar Astrophysics · Physics 2025-06-25 Boyang Ding , Junwei Zhao , Ruizhu Chen , Matthias Waidele , Sushant S. Mahajan , Oana Vesa

The last decade has seen a rapid development in asteroseismology thanks to the CoRoT and Kepler missions. With more detailed asteroseismic observations available, it is becoming possible to infer exactly how oscillations are driven and…

Solar and Stellar Astrophysics · Physics 2020-06-03 Yixiao Zhou , Martin Asplund , Remo Collet , Meridith Joyce

The analysis of the first solar-like targets done by CoRoT has shown that the oscillation amplitudes are about 25% below the theoretical amplitudes while the convective backgrounds are up to three times higher than in the solar case (Michel…

Solar and Stellar Astrophysics · Physics 2015-03-13 R. A. Garcia , S. Mathur , J. Ballot , C. Regulo