Experimental Astronomy

, Volume 7, Issue 2, pp 101–115

Astrometry from Space: New Design of the GAIA Mission

  • E. Høg
  • C. Fabricius
  • V. V. Makarov
Article

DOI: 10.1023/A:1007917410361

Cite this article as:
Høg, E., Fabricius, C. & Makarov, V.V. Experimental Astronomy (1997) 7: 101. doi:10.1023/A:1007917410361
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Abstract

An interferometric astrometric mission, aiming at accuracies at around the10 microarcsec level, was recommended as a high priority concept within thenew ESA Horizon 2000+ scientific programme. The original outline concept forsuch a mission, GAIA, presented its general feasibility but did not addressmany questions of implementation or optimisation. Another concept of aninterferometer for a scanning astrometric satellite is presented. It containsa simpler optical telescope and a more efficient detector system. The designutilizes the full resolution of all light in the dispersed fringes of aFizeau interferometer. A preliminary optimization of the satellite indicatesthat two telescope units with a baseline of 100 cm will achieve a precisionof 3, 8, 22, 68, 302 microarcsec for parallaxes of stars with V = 12, 14, 16, 18, 20 mag, respectively, from a 5 year mission. Simultaneousspectrophotometry of the entire spectrum of each star will be obtained with aresolution corresponding to intermediate band photometry. The expectedprecision of this photometry is about 0.003 mag for V = 16. The performance is good in crowded fields, at least up to one star per 5 arcsec2. A Hipparcos-type beam combiner of 150 cm width is placed in front of atelescope with 4 square apertures of 50 cm. The assumed focal length is f = 60 m and the field 0.5 degree diameter. The detector consists of CCDs used for time delayed integration (drift-scan.)

astrometryinstrumentation: interferometryphotometryspace vehiclestelescopes

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • E. Høg
    • 1
  • C. Fabricius
    • 1
  • V. V. Makarov
    • 1
  1. 1.Copenhagen University ObservatoryCopenhagenDenmark