Journal of Astrophysics and Astronomy

, Volume 21, Issue 3–4, pp 135–140 | Cite as

New high resolution observations of the solar diameter from space and ground with the microsatellite program PICARD

  • Luc Damé


The PICARD microsatellite mission will provide 2 to 6 years simultaneous measurements of the solar diameter, differential rotation and solar constant to investigate the nature of their relations and variabilities. The 100 kg satellite has a 40 kg payload consisting of 3 instruments which will provide an absolute measure (better than 10 milliarcsec) of the diameter and the solar shape, a measure of total solar irradiance, and UV and visible flux in selected wavelength bands. Now in Phase B, PICARD is expected to be launched before mid-2003. The engineering model of the diameter telescope will be used on ground simultaneously with the satellite to investigate the atmospheric bias and state on the possible accuracy of the ground measurements carried up to now. We review the scientific goals linked to the diameter measurement, present the payload, and give a brief overview of the program aspects.

Key words

Solar diameter solar shape long-period oscillations g-modes solar influence on climate 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Appourchaux, al. 2000, Observational Upper Limits for Low-Degree Solar g-Modes,Ap. J., in press.Google Scholar
  2. Appourchaux, T., Toutain, T. 1997, inSounding Solar and Stellar Interiors, SymposiumIAU, 181, (eds.) Janine Provost and Francois-Xavier Schmider, 5.Google Scholar
  3. Dame, L., Hersé, M., Thuillier, al. 1999, PICARD: Simultaneous Measurements of the Solar Diameter, Differential Rotation, Solar Constant and their Variations,Adv. in Space Research, 24(2), 205–214.CrossRefADSGoogle Scholar
  4. Fröhlich, C. the Phoebus Group 1998, inStructure and Dynamics of the Sun and Solar-like Stars (SOHO 6 /GONG 98),ESA SP-418, 67.Google Scholar
  5. Kuhn, J. R., Bogart, R., Bush, al. 1997, Precision Solar Astrometry from SOHO/MDI, inSounding Solar and Stellar Interiors, SymposiumIAU,181, (eds.) Janine Provost and Francois-Xavier Schmider, 103–110.Google Scholar
  6. Laclare, F., Delmas, C., Coin, J. P., Irbah, A. 1996, Measurements and Variations of the Solar Diameter,Solar Physics,166, 211–229.CrossRefADSGoogle Scholar
  7. Lean, J. 1997, The Sun’s Variable Radiation and its Relevance for Earth,Annu. Rev. Astron. Astrophys.,35, 33–67.CrossRefADSGoogle Scholar
  8. Ribes, E., Ribes, J. C., Barthalot, R. 1987, Evidence for a Larger-Sun with a Slower Rotation during the Seventeenth Century,Nature,326, 52–55.CrossRefADSGoogle Scholar
  9. Sadourny, R. 1994, Sensitivity of Climate to Long-term Variations of the Solar Output, inThe solar engine and its influence on terrestrial atmosphere and climate, (ed.) E. Nesme-Ribes, (Springer Verlag),NATO ASI Series I,25, 479–491.Google Scholar

Copyright information

© Indian Academy of Sciences 2000

Authors and Affiliations

  • Luc Damé
    • 1
  1. 1.Service d’Aéronomie du CNRSVerrières-le-BuissonFrance

Personalised recommendations