Keywords
Hipparcos
Gaia
How to Cite
Abstract
Astrometry – the measurement of stars' positions and movements – is one of the oldest disciplines in astronomy. In this article, Erik Høg tells the story of how accurate measurements of celestial bodies have developed over more than two millennia. From the first observations in antiquity to modern satellite missions, the technological advances that have gradually improved the accuracy of astronomical measurements are described. Special emphasis is placed on the Hipparcos satellite, whose data revolutionized our knowledge of stars' distances and proper motions. The article also looks ahead to the ESA Gaia mission, which is expected to deliver an even bigger leap in accuracy. With Gaia, astronomers will be able to map the structure and dynamics of the Milky Way in unprecedented detail. The article is both a historical overview and an introduction to the future of astrometric research.
References
[1] E. Høg (2008) "400 Years of Astrometry: From Tycho Brahe to Hipparcos", indeholdt i [3].
https://doi.org/10.1007/s10686-009-9156-7
[2] M. Perryman (2009) "Astronomical Applications of Astrometry - Ten Years of Exploitation of the Hipparcos Satellite Data", Cambridge University Press, 670 sider.
https://doi.org/10.1017/CBO9780511575242
[3] E. Høg om astrometriens historie: www.astro.ku.dk/~erik/History.pdf
[4] Gaia: ESAs oversigt: www.esa.int/science/gaia, projektets egne sider: www.rssd.esa.int/GAIA.
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