Information AboutAstrometry |
| CATEGORIES ABOUT ASTROMETRY | |
| astrometry | |
| astronomy | |
| astrological aspectsastrometry | |
| astronomy | |
| astrological aspects | |
| astronomical sub-disciplines | |
| astrological aspects | |
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Astrometry is a branch of Astronomy that deals with the positions of Star s and other Celestial Bodies , their distances and movements. It is one of the oldest subfields of the Science , the successor to the more qualitative study of Positional Astronomy . Astrometry dates back at least to Hipparchus , who compiled the first Catalogue Of Stars visible to him and in doing so invented the Brightness Scale basically still in use today. Modern astrometry was founded by Friedrich Bessel with his ''Fundamenta astronomiae'', which gave the mean position of 3222 stars observed between 1750 and 1762 by James Bradley . Apart from the fundamental function of providing Astronomer s with a Reference Frame to report their observations in, astrometry is also fundamental for fields like Celestial Mechanics , Stellar Dynamics and Galactic Astronomy . In Observational Astronomy , astrometric techniques help identify stellar objects by their unique motions. It is instrumental for keeping Time , in that UTC is basically the Atomic Time synchronized to Earth 's rotation by means of exact observations. Astrometry is also involved in creating the Cosmic Distance Ladder because it is used to establish Parallax distance estimates for stars in the Milky Way . ADVANCES IN ASTROMETRY
Astronomers use astrometric techniques for the tracking of Near-Earth Objects . It has been also been used to detect Extrasolar Planets by measuring the displacement they cause in their parent star's apparent position on the sky, due to their mutual orbit around the center of mass of the system. NASA's planned Space Interferometry Mission ( SIM PlanetQuest ) will utilize astrometric techniques to detect Terrestrial Planets orbiting 200 or so of the nearest Solar-type Stars . Astrometric measurements are used by Astrophysicist s to constrain certain models in Celestial Mechanics . By measuring the velocities of Pulsar s, it is possible to put a limit on the Asymmetry of Supernova explosions. Also, astrometric results are used to determine the distribution of Dark Matter in the galaxy. ASTROMETRICS Astrometrics is the Science of Stellar Measurement s and Motion . Astrometrics was used, during the 1990 s, to detect Extrasolar Gas Giant s Orbit ing various Solar System s. This was done by observing the " Stellar Wobble " of a star and calculating what kinds of Gravitational Force s would cause such motion; it was then determined that Planet ary forces must be affecting the stars in question. REFERENCES
IN FICTION In the '', the Astrometrics lab is the Set for various Scene s. SEE ALSO
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