Astrometric surveys
نویسندگان
چکیده
Astrometric surveys are a basic tool for galactic astronomy: they provide the only distance determination without assumption about the observed object as well as two components of the space velocity. A large number of stars, observed in a systematic way, yield to an unbiased sampling of the Galaxy and, for the most accurate surveys, of the brightest parts of Local Group galaxies, at larger and larger distances as the accuracy increases. The major astrometric surveys obtained or planned from ground-based observations or from space missions will be described, along with their main science drivers.
منابع مشابه
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