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We analyzed BiSON and GOLF/SoHO data with a new technique, to investigate p-mode power variation over solar cycle 23. We found a decrease in the mean velocity power of about 20% for BiSON during the ascending phase, in agreement with…

Astrophysics · Physics 2008-10-13 R. Simoniello , D. Salabert , R. A. Garcia

The recent claims of g-mode detection have restarted the search for these potentially extremely important modes. These claims can be reassessed in view of the different data sets available from the SoHO instruments and ground-based…

Solar and Stellar Astrophysics · Physics 2018-09-26 T. Appourchaux , P. Boumier , J. W. Leibacher , T. Corbard

We analyze more than 5000 days of high-quality Sun-as-a-star, radial velocity GOLF and photometric VIRGO/SPM helioseismic observations to extract precise estimates of the visibilities of the low-degree p modes and the m-height ratios of the…

Solar and Stellar Astrophysics · Physics 2015-05-27 David Salabert , Jerome Ballot , Rafael A. Garcia

The GOLF instrument on board SoHO has been in operation for almost 25 years but aging of the instrument has now strongly affected its performance, especially in the low-frequency p-mode region. At the end of the SoHO mission, the…

Solar and Stellar Astrophysics · Physics 2022-02-02 S. N. Breton , P. L. Pallé , R. A. García , M. Fredslund Andersen , F. Grundahl , J. Christensen-Dalsgaard , H. Kjeldsen , S. Mathur

The recent claimed detection of g modes was obtained from the analysis of the power spectrum of the time series of round-trip travel time of p modes. The goal of this paper is to reproduce these results on which the claims are based for…

Solar and Stellar Astrophysics · Physics 2019-04-24 T. Appourchaux , T. Corbard

Birmingham Solar Oscillations Network (BiSON) instruments use resonant scattering spectrometers to make unresolved Doppler velocity observations of the Sun. Unresolved measurements are not homogenous across the solar disc and so the…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New

Solar magnetism is measured with different indexes: for instance the MPSI and the MWSI, number of sunspots, radio flux at 10.7 cm, Ca II K, Mg II K, EUV, He I or L_alpha. Bachmann & White (1994) had compared these indicators of the solar…

Astrophysics · Physics 2008-10-13 S. Mathur , S. J. Jimenez-Reyes , R. A. Garcia

The high-quality, full-disk helioseismic observations continuously collected by the spectrophotometer GOLF and the three photometers VIRGO/SPMs onboard the SoHO spacecraft for 17 years now (since April 11, 1996, apart from the SoHO…

Solar and Stellar Astrophysics · Physics 2013-09-18 D. Salabert , R. A. Garcia , A. Jimenez

Over the past 15 years, our knowledge of the interior of the Sun has tremendously progressed by the use of helioseismic measurements. However, to go further in our understanding of the solar core, we need to measure gravity (g) modes.…

Below 1 mHz, the power spectrum of helioseismic velocity measurements is dominated by the spectrum of convective motions (granulation and supergranulation) making it difficult to detect the low-order acoustic modes and the gravity modes. We…

Astrophysics · Physics 2008-10-31 S. Lefebvre , R. A. Garcia , S. J. Jimenez-Reyes , S. Turck-Chieze , S. Mathur

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…

A time series of GONG Dopplergrams for the period 10-14 May 1997 from Udaipur and Big Bear sites has been used to measure the velocity fluctuations in the sunspot (NOAA active region 8038) and quiet photosphere simultaneously. We observe…

Astrophysics · Physics 2015-06-24 Brajesh Kumar , R. Jain , S. C. Tripathy , Hari Om Vats , M. R. Deshpande

All p-mode parameters vary with time as a response to the changes induced by the cyclic behavior of solar magnetic activity. After the unusual long solar-activity minimum between cycles 23 and 24, where the p-mode parameters have shown a…

Solar and Stellar Astrophysics · Physics 2013-06-18 R. A. Garcia , D. Salabert , S. Mathur , C. Regulo , J. Ballot , G. R. Davies , A. Jimenez , R. Simoniello

Solar flares presumably have an impact on the deepest layers of the solar atmosphere and yet the observational evidence for such an impact is scarce. Using ten years of measurements of the Na D$_{1}$ and Na D$_2$ Fraunhofer lines, measured…

Solar and Stellar Astrophysics · Physics 2010-05-21 G. Cessateur , M. Kretzschmar , T. Dudok de Wit , P. Boumier

Frequencies of low-degree solar p modes are sensitive to activity over the entire Sun, including the unobservable far-side hemisphere. When frequency shifts extracted from week-long BiSON datasets are fitted to a linear combination of…

Solar and Stellar Astrophysics · Physics 2026-01-06 William J. Chaplin , Rachel Howe , Sarbani Basu , Yvonne Elsworth , Steven J. Hale , Emily J. Hatt , Eleanor Murray , Martin B. Nielsen

In a recent study [1], we demonstrated a multi-heterodyne differential absorption lidar (DIAL) for greenhouse gas monitoring utilizing solid targets. The multi-frequency absorption measurement was achieved using electro-optic dual-comb…

Optics · Physics 2024-06-27 William Patiño Rosas , Nicolas Cézard

We present a new and highly efficient algorithm for computing a power spectrum made from evenly spaced data which combines the noise-reducing advantages of the weighted fit with the computational advantages of the Fast Fourier Transform…

Solar and Stellar Astrophysics · Physics 2015-05-28 S. T. Fletcher , A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New

A histogram display of the solar neutrino capture-rate measurements made by the GALLEX experiment appears to be bimodal, but that of the follow-on GNO experiment does not. To assess the significance of these results, we introduce a…

High Energy Physics - Phenomenology · Physics 2009-11-13 P. A. Sturrock

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

Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…

Solar and Stellar Astrophysics · Physics 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall
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