zenith telescope — An Etymological Dictionary of Astronomy and Astrophysics

zenith telescope

تلسکوپ ِ سرسو، دوربین ِ ~

teleskop-e sarsu, dvrbin-e ~

Fr.: télescope zénithal

A → telescope that is mounted on a → vertical axis or moves only a small amount from the vertical. It is primarily used to determine positional measurement of stars moving near the → zenith. The advantage is that
there is no → atmospheric refraction occurring at the zenith. If a star on one night passes through the center of eyepiece, one must observe it six month later, and see if the star has been offset by the center. A shift would mean a measure of parallax.

An Etymological Dictionary of Astronomy and Astrophysics

English-French-Persian

فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک