Surveying the sky

An astrometric experiment in 1925 was the beginning of a development, which astronomer Erik Høg at the Niels Bohr Institute further developed from 1960. He devised a new method for accurate measurement of the stars in the sky that led ESA to launch the first major astrometry satellite Hipparcos in 1989. A scientific highlight is the star catalogue Tycho-2 from the year 2000, which describes the positions and movements of 2.5 million stars and is now absolutely essential to controlling satellites and for astronomical observations.

  • A 400 year era

    En epoke over 400 årA 400 year era
    Our most famous astronomer, Tycho Brahe was directly under the king, who let him build an observatory on the island Hven in Øresund.

  • Astrometry

    Astrometry is the branch of astronomy that Tycho Brahe practised by measuring the position of stars.

  • Development of photoelectric astrometry

    Development of photoelectric astrometryDevelopment of photoelectric astrometry
    Erik Høg, an astronomer at the University of Copenhagen, worked for 15 years at the observatory in Hamburg.

  • Astrometry in space

    Astrometry in spaceAstrometry in space
    In 1975 ESA asked Erik Høg whether he would take part in the development of a satellite for astrometry.

  • The Gaia Mission – a new tiger leap in astrometry

    Gaia - et kvantespring for astrometrienThe Gaia Mission - a new tiger leap in astrometry
    The first satellite, Hipparcos brought a tiger leap for astrometry. Next big leap was the Gaia satellite, which is a million times more efficient