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Related papers: Calibrating 15 years of GOLF data

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Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…

We use high spatial and temporal resolution observations, simultaneously obtained with the New Vacuum Solar Telescope and Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, to investigate the high-frequency…

Solar and Stellar Astrophysics · Physics 2018-03-28 Feng Wang , Hui Deng , Bo Li , Song Feng , Xianyong Bai , Linhua Deng , Yunfei Yang , Zhike Xue , Rui Wang

In high-resolution solar physics, the volume and complexity of photometric, spectroscopic, and polarimetric ground-based data significantly increased in the last decade reaching data acquisition rates of terabytes per hour. This is driven…

Instrumentation and Methods for Astrophysics · Physics 2018-05-23 C. Denker , C. Kuckein , M. Verma , S. J. González Manrique , A. Diercke , H. Enke , J. Klar , H. Balthasar , R. E. Louis , E. Dineva

We describe systematic changes in the centroid frequencies and the splitting coefficients as found using data from MDI on board SOHO, covering cycle 23. The data allow us to construct a seismic map of the evolving solar activity -- covering…

Astrophysics · Physics 2007-05-23 W. A. Dziembowski , Philip R. Goode

We have compiled a catalog of solar flares as observed by the Extreme ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory (SOHO) spacecraft and the GOES spacecraft over a span from 1997 to 2010. During…

Solar and Stellar Astrophysics · Physics 2020-08-05 Sumanth A. Rotti , Petrus C. H. Martens , Berkay Aydin

The century long (1914-2007) $H_{\alpha}$ (656.28 nm) spectroheliograms from Kodaikanal Solar Observatory (KSO) have been recently digitised. Using these newly calibrated, processed images we study the evolution of dark elongated on disk…

Solar and Stellar Astrophysics · Physics 2017-11-08 Subhamoy Chatterjee , Manjunath Hegde , Dipankar Banerjee , B. Ravindra

Reconstructions of solar spectral irradiance - especially in the ultraviolet (UV) range - are crucial for understanding Earth's climate system. Although total solar irradiance (TSI) has been thoroughly investigated, the spectral composition…

The solar corona is a highly-structured plasma which can reach temperatures of more than ~2 MK. At low frequencies (decimetric and metric wavelengths), scattering and refraction of electromagnetic waves are thought to considerably increase…

Directly imaging Earth-like exoplanets (``exoEarths'') with a coronagraph instrument on a space telescope requires a stable wavefront with optical path differences limited to tens of picometers RMS during exposure times of a few hours.…

The solar modulation of galactic cosmic rays (GCR) can be studied in detail by examining long-term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium…

Space Physics · Physics 2016-03-10 P. Kühl , R. Gómez-Herrero , B. Heber

Recent precise observations of solar global parameters are used to calibrate an upgraded solar model which takes into account magnetic fields in the solar interior. Historical data about sunspot numbers (from 1500 to the present) and solar…

Astrophysics · Physics 2015-06-24 Sabatino Sofia , Linghuai H. Li

In this letter, we explore the relationship between the solar seismic radius and total solar irradiance (TSI) during last two solar cycles using the uninterrupted data from space-borne instruments onboard {\it SoHO} and {\it SDO}. The…

Solar and Stellar Astrophysics · Physics 2018-06-06 Kiran Jain , S. C. Tripathy , F. Hill

We calculate accurate solar models and report the detailed time dependences of important solar quantities. We use helioseismology to constrain the luminosity evolution of the sun and report the discovery of semi-convection in evolved solar…

Astrophysics · Physics 2008-11-26 John N. Bahcall , M. H. Pinsonneault , Sarbani Basu

The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value,…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. Jimenez , R. A. Garcia , P. L. Palle

During the last few years a number of works have proposed that planetary harmonics regulate solar oscillations and the Earth climate. Herein I address some critiques. Detailed analysis of the data do support the planetary theory of solar…

Geophysics · Physics 2014-12-02 Nicola Scafetta

We recalibrate a standard solar model seismologically to estimate the main-sequence age of the Sun. Our procedure differs from what we have done in the past by removing from the observed frequencies the effect of hydrogen ionization and the…

Astrophysics · Physics 2015-05-13 Günter Houdek , Douglas Gough

We present a program designed to obtain age-rotation measurements of solar-type dwarfs to be used in the calibration of gyrochronology relations at ages of several Gyr. This is a region of parameter space crucial for the large-scale study…

Solar and Stellar Astrophysics · Physics 2015-05-30 Julio Chanamé , Iván Ramírez

We study the sensitivity of the sound speed to relativistic corrections of the equation of state (EOS) in the standard solar model by means of a helioseismic forward analysis. We use the latest GOLF/SOHO data for $\ell = 0,1,2,3$ modes to…

Astrophysics · Physics 2007-05-23 A. Bonanno , A. L. Murabito , L. Paterno'

The Luminosity Oscillations Imager (LOI) of the Variability of Solar Irradiance and Gravity Oscillations (VIRGO) instrument aboard the SoHO mission has been operating for almost the past 30 years. I report on the effect of solar activity…

Solar and Stellar Astrophysics · Physics 2026-01-21 Thierry Appourchaux

Unlike other stars, the surface of the Sun can be spatially resolved to a high degree of detail. But the Sun can also be observed as if it was a distant star. The availability of solar disk-resolved and disk-integrated spectra offers an…

Solar and Stellar Astrophysics · Physics 2014-11-27 Alexei Pevtsov , Luca Bertello , Brian Harker , Mark Giampapa , Andrew Marble
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