#proper motion

• Arcturus — The proper name of the brightest star in the constellation Boötes and the fourth-brightest star in the entire night sky, being an orange giant located approximately 36.7 light-years from Earth. In mythology, the name originates from ancient Greek and means 'guardian of the bear', due to its structural proximity to the Ursa Major constellation.
• Astrometric — Belonging to astrometry, relating to astrometry; referring to the precise geometric measurement of positions, angular distances, and proper motions of celestial bodies on the celestial sphere. This term defines the methods, coordinate catalogs, instruments (such as scanning telescopes), or satellite data (such as those provided by the Gaia mission) used to establish fundamental star charts.
• Astrometry — A fundamental branch of positional astronomy that deals with the precise geometric measurement of positions, proper motions, angular distances, and parallaxes of celestial bodies on the celestial sphere. This field establishes space reference systems and fundamental coordinates indispensable for galactic mapping, calculating planetary orbits, or detecting subtle gravitational perturbations generated by exoplanets.