Differential Proper Motion Spin of the Hipparcos and Gaia Celestial Reference Frames

  title={Differential Proper Motion Spin of the Hipparcos and Gaia Celestial Reference Frames},
  author={Valeri V. Makarov},
  journal={The Astronomical Journal},
  • V. Makarov
  • Published 8 August 2022
  • Physics
  • The Astronomical Journal
The Hipparcos catalog provides the first epoch of the celestial reference frame (CRF) in the optical domain and serves as an indispensable tool to verify and improve the Gaia CRF for the brighter stars (V < 11 mag) and to identify the elusive astrometric binary stars with dim or invisible companions, including long-period exoplanets. The systems of positions in Hipparcos and Gaia cannot be directly compared, because they refer to two different mean epochs. It is shown that the proper motion… 



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    Monthly Notices of the Royal Astronomical Society
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