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Related papers: Detecting individual gravity modes in the Sun: Chi…

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Recently, Karoff and Kjeldsen (2008) presented evidence of strong correlation between the energy in the high-frequency part (5.3<\nu<8.3 mHz) of the acoustic spectrum of the Sun and the solar X-ray flux. They have used disk-integrated…

Solar and Stellar Astrophysics · Physics 2015-05-18 Brajesh Kumar , Savita Mathur , R. A. Garcia , P. Venkatakrishnan

The low degree splittings obtained from one year of GOLF data analysis are combined with the MDI medium-l 144-day splittings in order to infer the solar internal rotation as a function of the radius down to $0.2R_\odot$. Several inverse…

Astrophysics · Physics 2013-08-01 T. Corbard , M. P. Di Mauro , T. Sekii , the GOLF team

Frequency and rotational splittings of the solar f-modes are estimated from the GONG data. Contrary to earlier observations the frequencies of f-modes are found to be close to the theoretically computed values for a standard solar model.…

Astrophysics · Physics 2008-11-26 H. M. Antia

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

The SoHO spacecraft made astrophysicists achieve a major breakthrough in the knowledge of the Sun. In helioseismology, both GOLF and MDI experiments aboard SoHO greatly improve the accuracy of seismic data. More specifically, the detection…

Astrophysics · Physics 2009-11-07 S. Couvidat , S. Turck-Chieze , A. G. Kosovichev

The Sun-as-a-star helioseismic spectrophotometer GOLF and photometer VIRGO instruments onboard the SoHO spacecraft are collecting high-quality, continuous data since April 1996. We analyze here these unique datasets in order to investigate…

Solar and Stellar Astrophysics · Physics 2014-11-04 D. Salabert , R. A. Garcia , A. Jimenez

We investigate the behavior of the intermediate-degree mode frequencies of the sun during the current extended minimum phase to explore the time-varying conditions in the solar interior. Using contemporaneous helioseismic data from GONG and…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. C. Tripathy , K. Jain , F. Hill , J. W. Leibacher

The primary challenge of GOLF-NG (Global Oscillations at Low Frequency New Generation) is the detection of the low-frequency solar gravity and acoustic modes, as well as the possibility to measure the high-frequency chromospheric modes. On…

Since the beginning of this century we have attended a blooming of the gravity-mode research thanks to the unprecedented quality of the data available, either from space with SoHO, or from the ground-based networks as BiSON or GONG. From…

Solar activity has significantly changed over the last two Schwabe cycles. After a long and deep minimum at the end of Cycle 23, the weaker activity of Cycle 24 contrasts with the previous cycles. In this work, the response of the solar…

Solar and Stellar Astrophysics · Physics 2015-06-24 D. Salabert , R. A. Garcia , S. Turck-Chieze

Recently, several efforts have been made to identify the seismic signatures of flares and magnetic activity in the Sun and Sun-like stars. In this work, we have analyzed the disk-integrated velocity and intensity observations of the Sun…

Solar and Stellar Astrophysics · Physics 2017-10-18 Brajesh Kumar , Savita Mathur , Rafael A. Garcia , Antonio Jimenez

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

Internal gravity waves have been observed in the Earth's atmosphere and oceans, on Mars and Jupiter, and in the Sun's atmosphere. Despite ample evidence for the existence of propagating gravity waves in the Sun's atmosphere, we still do not…

Solar and Stellar Astrophysics · Physics 2021-01-20 Daniele Calchetti , Stuart M. Jefferies , Bernhard Fleck , Francesco Berrilli , Dmitriy V. Shcherbik

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

Young and active stars generally have regular, almost sinusoidal, patterns of variability attributed to their rotation, while the majority of older and less active stars, including the Sun, have more complex and non-regular light-curves…

Solar and Stellar Astrophysics · Physics 2020-04-22 E. M. Amazo-Gómez , A. I. Shapiro , S. K. Solanki , N. A. Krivova , G. Kopp , T. Reinhold , M. Oshagh , A. Reiners

The Global Oscillations at Low Frequencies instrument aboard the Solar and Heliospheric Observatory has provided over two decades of continuous, high-precision data, enabling detailed measurements of the Sun's oscillation frequencies. These…

Solar and Stellar Astrophysics · Physics 2025-03-10 Christopher J. Lombardi , Alexander G. Kosovichev , Keitarou Matsumoto

Although there are now some tentative signs that the start of cycle 24 has begun there is still considerable interest in the somewhat unusual behaviour of the current solar minimum and the apparent delay in the true start of the next cycle.…

Solar and Stellar Astrophysics · Physics 2010-03-23 Stephen Fletcher , Roger New , Anne-Marie Broomhall , William Chaplin , Yvonne Elsworth

Solar inertial modes are quasi-toroidal modes of the Sun that are of practical interest as they allow probing the deep convection zone. Since 2010, solar images of the photospheric magnetic field are made available by HMI onboard the Solar…

Solar and Stellar Astrophysics · Physics 2025-02-10 Neelanchal Joshi , Zhi-Chao Liang , Damien Fournier , Laurent Gizon

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

Context. Solar gravity modes (g modes) are buoyancy waves trapped in the solar radiative zone that have been very difficult to detect at the surface. Solar g modes would complement solar pressure modes (p modes) in probing the central…

Solar and Stellar Astrophysics · Physics 2019-09-04 Vincent G. A. Böning , Huanchen Hu , Laurent Gizon