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Related papers: Cyclic Changes of the Sun's Seismic Radius

200 papers

The correlation between solar irradiance and the 11-year solar activity cycle is evident in the body of measurements made from space, which extend over the past four decades. Models relating variation in solar irradiance to photospheric…

Solar and Stellar Astrophysics · Physics 2015-07-07 K. L. Yeo , N. A. Krivova , S. K. Solanki

We analyze Sun-as-a-star observations spanning over solar cycles 22 -- 24 from the ground-based network BiSON and solar cycles 23 -- 24 collected by the space-based VIRGO and GOLF instruments on board the {\it SoHO} satellite. Using…

Solar and Stellar Astrophysics · Physics 2019-01-30 Kiran Jain , Sushanta Tripathy , Frank Hill , David Salabert , Rafael A. Garcia , Anne-Marie Broomhall

The Solar Diameter Monitor measured the duration of solar meridian transits during the 6 years 1981 to 1987, spanning the declining half of solar cycle 21. We have combined these photoelectric measurements with models of the solar…

Astrophysics · Physics 2008-11-26 T. M. Brown , J. Christensen-Dalsgaard

Thanks to space-borne experiments such as the AMS-02 and PAMELA missions in low-Earth orbit, along with the Voyager spacecrafts in the interstellar space, a large collection of multi-channel and time-resolved Galactic cosmic ray (GCR) data…

High Energy Astrophysical Phenomena · Physics 2019-08-06 Bruna Bertucci , Emanuele Fiandrini , Behrouz Khiali , Nicola Tomassetti

In this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985 - 2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

With the ultimate aim of using the fundamental or $f$-mode to study helioseismic aspects of turbulence-generated magnetic flux concentrations, we use randomly forced hydromagnetic simulations of a piecewise isothermal layer in two…

Solar and Stellar Astrophysics · Physics 2015-06-19 Nishant K. Singh , Axel Brandenburg , S. M. Chitre , Matthias Rheinhardt

In this dissertation, several components of large-scale solar flows are studied observationally: solar equatorial Rossby waves (waves of radial vorticity), large-scale convection, and surface flows around active regions. Maps of horizontal…

Solar and Stellar Astrophysics · Physics 2023-01-25 Bastian Proxauf

A seismic model for the Sun calculated using the accurate helioseismic data predicts a lower $^{8}{B}$ neutrino flux as compared to the standard solar model (SSM). However, there persists a discrepancy between the predicted and measured…

High Energy Physics - Phenomenology · Physics 2009-11-07 Sandhya Choubey , Srubabati Goswami , Kamales Kar , H. M. Antia , S. M. Chitre

The action of the atmospheric seeing is blurring, image stretching and image motion. This happens even to the image of the Sun which is more than half degree wide. Low frequency seeing components affect the solar diameter values measured…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Costantino Sigismondi

The Sun's axisymmetric flows, differential rotation and meridional flow, govern the dynamics of the solar magnetic cycle and variety of methods are used to measure these flows, each with its own strengths and weaknesses. Flow measurements…

Solar and Stellar Astrophysics · Physics 2021-09-08 Sushant S. Mahajan , David H. Hathaway , Andrés Muñoz-Jaramillo , Petrus C. Martens

Active regions are open wounds in the Sun's surface. Seismic oscillations from the interior pass through them into the atmosphere, changing their nature in the process to fast and slow magneto-acoustic waves. The fast waves then partially…

Solar and Stellar Astrophysics · Physics 2013-09-12 Paul S. Cally , Hamed Moradi

This review has two parts. The first part summarizes the current observational constraints on fluctuations in the solar medium deep within the solar Radiative Zone, and shows how the KamLAND and SNO-salt data combine to make the…

High Energy Physics - Phenomenology · Physics 2007-05-23 C. P. Burgess N. S. Dzhalilov , M. Maltoni , T. I. Rashba , V. B. Semikoz , M. Tortola , J. W. F. Valle

Helioseismology has taught us a great deal about the stratification and kinematics of the solar interior, sufficient for us to embark upon dynamical studies more detailed than have been possible before. The most sophisticated studies to…

Solar and Stellar Astrophysics · Physics 2015-06-02 D. O. Gough

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

We use helioseismic data from ground and space-based instruments to analyze how solar rotation has changed since the beginning of solar Cycle 23 with emphasis on studying the differences between Cycles 23 and 24. We find that the nature of…

Solar and Stellar Astrophysics · Physics 2019-10-02 Sarbani Basu , H. M. Antia

We apply computational seismic holography to high-frequency helioseismic observations of the quiet Sun from SDO/HMI to locate predominant sources of seismic emission with respect to the structure of the solar granulation. The regions of…

Solar and Stellar Astrophysics · Physics 2013-07-05 Charles Lindsey , Alina Donea

The Sun is the only star where the superficial turbulent convection can be observed at very high spatial resolution. The Solar Dynamics Observatory (SDO) has continuously observed the full Sun from space with multi-wavelength filters since…

Solar and Stellar Astrophysics · Physics 2021-08-18 J. Ballot , T. Roudier , J. M. Malherbe , Z. Frank

We study the response of the low-degree solar p-mode frequencies to the unusual extension of the minimum of solar surface activity since 2007. Helioseismic observations collected by the space-based, Sun-as-a-star GOLF instrument and by the…

Solar and Stellar Astrophysics · Physics 2010-05-06 D. Salabert , R. A. Garcia , P. L. Palle , S. J. Jimenez-Reyes

We argue that a variety of solar data suggest that the activity-cycle timescale variability of the total irradiance, is produced by structural adjustments of the solar interior. Assuming these adjustments are induced by variations of…

Astrophysics · Physics 2009-10-31 L. H. Li , S. Sofia