FIRST RESULTS FROM VIRGO, THE EXPERIMENT FOR HELIOSEISMOLOGY AND SOLAR IRRADIANCE MONITORING ON SOHO

@article{Frhlich1997FIRSTRF,
  title={FIRST RESULTS FROM VIRGO, THE EXPERIMENT FOR HELIOSEISMOLOGY AND SOLAR IRRADIANCE MONITORING ON SOHO},
  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},
  year={1997},
  volume={170},
  pages={1-25}
}
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… 

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References

SHOWING 1-10 OF 21 REFERENCES

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