When telescopes became commonplace, setting circles sped measurements James Bradley first tried to measure stellar parallaxes in 1729.
His cataloguing of 3222 stars was refined in 1807 by Friedrich Bessel, the father of modern astrometry.
Automated plate-measuring machines and more sophisticated computer technology of the 1960s allowed more efficient compilation of star catalogues.
In the 1980s, charge-coupled devices (CCDs) replaced photographic plates and reduced optical uncertainties to one milliarcsecond.
This technology made astrometry less expensive, opening the field to an amateur audience. In 1989, the European Space Agency's Hipparcos satellite took astrometry into orbit, where it could be less affected by mechanical forces of the Earth and optical distortions from its atmosphere.
Operated from 1989 to 1993, Hipparcos measured large and small angles on the sky with much greater precision than any previous optical telescopes.
Operated from 1989 to 1993, Hipparcos measured large and small angles on the sky with much greater precision than any previous optical telescopes.
The European Space Agency's Gaia Mission, launched in 2013, applies astrometric techniques in its stellar census.
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