author={Claus Fr{\"o}hlich and Bo Nyborg Andersen and Thierry Appourchaux and Gabrielle Berthomieu and Dominique A. H. Crommelynck and Vicente Domingo and Alain Fichot and Wolfgang Finsterle and Mar{\'i}a F. G{\'o}mez and Douglas Gough and A. C. Lopez Jimenez and Torben Leifsen and Marcel Lombaerts and Judit Pap and Janine Provost and T. Roca cort{\'e}s and Jos{\'e} Romero and Hansj{\"o}rg Roth and Takashi Sekii and Udo Telljohann and Thierry Toutain and Christoph Wehrli},
  journal={Solar Physics},
First results from the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) on the ESA/NASA Mission SOHO (Solar and Heliospheric Observatory) are reported. The observations started mid-January 1996 for the radiometers and sunphotometers and near the end of March for the luminosity oscillation imager. The performance of all the instruments is very good, and the time series of the first 4–6 months are evaluated in terms of solar irradiance variability, solar background… 

Solar cycle variation of νmax in helioseismic data and its implications for asteroseismology

The frequency, νmax, at which the envelope of pulsation power peaks for solar-like oscillators is an important quantity in asteroseismology. We measure νmax for the Sun using 25 yr of Sun-as-a-star

Photospheric activity of the Sun with VIRGO and GOLF: Comparison with standard activity proxies

We study the variability of solar activity using new photospheric proxies originally developed for the analysis of stellar magnetism with the CoRoT and Kepler photometric observations. These proxies

Mode visibilities in radial velocity and photometric Sun-as-a-star helioseismic observations

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

The helioseismological CORONAS-F DIFOS experiment

The CORONAS-F DIFOS experiment continues the CORONAS-I studies started in 1994, devoted to investigations of solar global oscillations. CORONAS-F was launched July 31, 2001. Variations in the

On the signatures of flare-induced global waves in the Sun: GOLF and VIRGO observations

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

Hydrodynamical simulations of convection-related stellar micro-variability. II. The enigmatic granul

We used a series of CO5BOLD hydrodynamical model atmospheres covering stellar objects from white dwarfs to red giants to derive theoretical estimates of the photometric and photocentric stellar

Modelling the rotational modulation of the Sun as a star

We analyse the time variability of the total solar irradiance (TSI) as measured by VIRGO/SoHO in order to model the variability of the Sun as a star. Apart from the phases near the minimum at the

Study of the Solar Cycle Dependence of Low-Degree p-Modes with Michelson Doppler Imager and VIRGO

Studying variations of observational properties of low-degree solar acoustic p-modes (radial, dipole, and quadrupole) with the activity cycle is important for understanding potential effects of the

First View of the Solar Core from Golf Acoustic Modes

After 8 months of nearly continuous measurements the GOLF instrument, aboard SOHO, has detected acoustic mode frequencies of more than 100 modes, extending from 1.4 mHz to 4.9 mHz. In this paper, we

Tri-Phonic Helioseismology: Comparison of Solar p Modes Observed by the Helioseismology Instruments Aboard SOHO

The three helioseismology instruments aboard SOHO observe solar p modes in velocity (GOLF and MDI) and in intensity (VIRGO and MDI). Time series of two months duration are compared and confirm that



VIRGO: Experiment for helioseismology and solar irradiance monitoring

The scientific objective of the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) is to determine the characteristics of pressure and internal gravity oscillations by

Observations of solar irradiance variability.

Measurements of total solar irradiance show the irradiance to have been variable throughout the first 153 days of observations, and suggest that considerable energy storage occurs within the convection zone in solar active regions.

The sun in time

Various papers on solar science are presented. The optics considered include: variability of solar irradiance, sunspot number, solar diameter, and solar wind properties; theory of luminosity and

Nonfacular solar luminosity variations

Solar limb photometry data obtained in 1990 shows a decline in the active region facular contribution to the solar irradiance from the previous year, in accord with the maximum in the sunspot cycle

Some theoretical remarks on solar oscillations

The properties of the- linear modes of oscillation of a nonrotating nonmagnetic star, with particular reference to the sun, are briefly described. The most likely mechanisms by which they might be

Solar pulsational stability – I. Pulsation-mode thermodynamics

It is not currently known what excites solar five-minute oscillations. Of the two most plausible possibilities, thermal overstability and stochastic excitation by turbulent convection, the single

A new inversion for the hydrostatic stratification of the sun

Inversions for the spherically symmetric component of the hydrostatic stratification of the Sun are presented. These employ the Backus-Gilbert optimally localized averaging procedure applied to

The variation in the strength of low-ℓ solar p-modes: 1981–92

The acoustic eigenmodes of the Sun are a well-recognized probe of the structure of the solar interior. We report here on a measurement of the strength of the low-l p-mode oscillations throughout a

Characteristics of solar p-modes - Results from the IPHIR experiment

Solar p-modes were observed in irradiance during more than 160 days by the IPHIR experiment on the USSR PHOBOS Mission in 1988. They are characterized by their frequency, splitting, linewidth and

SOLCON Solar Constant Observations from the ATLAS Missions

The solar constant observations obtained by the SOLCON/ATLAS experiment during the three successive missions are presented based on the Space Absolute Radiometric Reference (SARR) defined during the