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相关论文: GONG p-mode parameters through two solar cycles

200 篇论文

Frequency splitting coefficients from Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) observations covering the period 1995--2001 are used to study temporal variations in the solar rotation rate at high latitudes.…

天体物理学 · 物理学 2009-11-07 H. M. Antia , Sarbani Basu

We present a new and up-to-date analysis of the solar low-degree $p$-mode parameter shifts from the Birmingham Solar-Oscillations Network (BiSON) over the past 22 years, up to the end of 2014. We aim to demonstrate that they are not…

太阳与恒星天体物理 · 物理学 2015-11-04 R. Howe , G. R. Davies , W. J. Chaplin , Y. P. Elsworth , S. J. Hale

In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140…

Solar p-mode oscillations exhibit a systematic offset towards higher frequencies due to shortcomings in the 1D stellar structure models, especially, the lack of turbulent pressure in the superadiabatic layers just below the optical surface,…

太阳与恒星天体物理 · 物理学 2016-07-06 Zazralt Magic , Achim Weiss

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"…

太阳与恒星天体物理 · 物理学 2023-11-29 Hidetaka Kuniyoshi , Munehito Shoda , Richard J. Morton , Takaaki Yokoyama

We have analysed temporal evolution in centroid frequencies and splitting coefficients of solar f-modes obtained from MDI/SOHO. The data were divided into 20 sets covering a period from May 1, 1996 to August 31, 2000. The variation in…

天体物理学 · 物理学 2007-05-23 Kiran Jain , S. C. Tripathy , A. Bhatnagar

In a previous study, Huang et al. (2023) used the Alfven Wave Solar atmosphere Model (AWSoM), one of the widely used solar wind models in the community, driven by ADAPT-GONG magnetograms to simulate the solar wind in the last solar cycle…

太阳与恒星天体物理 · 物理学 2024-03-05 Zhenguang Huang , Gabor Toth , Nishtha Sachdeva , Bart van der Holst

Turbulent motions in stellar convection zones generate acoustic energy, part of which is then supplied to normal modes of the star. Their amplitudes result from a balance between the efficiencies of excitation and damping processes in the…

天体物理学 · 物理学 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret

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…

Context: Solar sectoral Rossby waves have only recently been unambiguously identified in Helioseimsic and Magnetic Imager (HMI) and Michelson Doppler Imager (MDI) maps of flows near the solar surface. So far this has not been done with the…

太阳与恒星天体物理 · 物理学 2020-03-18 Chris S. Hanson , Laurent Gizon , Zhi-Chao Liang

We study the solar-cycle variations of solar p-mode travel time for different wave packets to probe the magnetic fields at the base of the solar convection zone. We select the wave packets which return to the same spatial point after…

天体物理学 · 物理学 2009-11-07 Dean-Yi Chou , Alexandr Serebryankiy

We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1 milliHz, consistent with the…

天体物理学 · 物理学 2009-11-11 H. Bruntt , H. Kjeldsen , D. L. Buzasi , T. R. Bedding

Solar gravity modes are considered as the {\it Rosetta Stone} for probing and subsequently deciphering the physical properties of the solar inner-most layers. Recent claims of positive detection therefore shed some new light on the…

太阳与恒星天体物理 · 物理学 2022-11-30 Kévin Belkacem , Charly Pinçon , Gaël Buldgen

A new fitting methodology is presented which is equally well suited for the estimation of low-, medium-, and high-degree mode parameters from $m$-averaged solar oscillation power spectra of widely differing spectral resolution. This method,…

太阳与恒星天体物理 · 物理学 2015-04-30 J. Reiter , E. J. Rhodes , A. G. Kosovichev , J. Schou , P. H. Scherrer , T. P. Larson

Based on the Solar Standard Model we developed a solar model in hydrostatic equilibrium using two polytropes that describes both the "radiative" and "convective" zones of the solar interior. Then we apply small periodic and adiabatic…

天体物理学 · 物理学 2007-05-23 G. A. Pinzon

Theoretically calculated power spectra are compares with observed solar p-mode velocity power spectra over a range of mode degree and frequency. The depth for the sources responsible for exciting p-modes of frequency 2.0 mHz is determined…

天体物理学 · 物理学 2009-10-31 Pawan Kumar , Sarbani Basu

The Sun's surface vibrates in characteristic 5-minute oscillations, known as p-modes, generated by sound waves trapped within the convection zone. Although these oscillations have long been hypothesized to reach into the solar wind, direct…

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…

Frequency separations used to infer global properties of stars through asteroseismology can change depending on the strength and at what epoch of the stellar cycle the p-mode frequencies are measured. In the Sun these variations have been…

太阳与恒星天体物理 · 物理学 2015-05-20 O. L. Creevey , D. Salabert , R. A. Garcia

The Sun is a variable star whose magnetic activity and total irradiance vary on a timescale of approximately 11 years. The current activity minimum has attracted considerable interest because of its unusual duration and depth. This raises…

太阳与恒星天体物理 · 物理学 2009-07-21 A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , S. T. Fletcher , R. New