Zenith
The zenith (
Origin
The word zenith derives from an inaccurate reading of the
Relevance and use
The term zenith sometimes means the
In a scientific context, the zenith is the direction of reference for measuring the zenith angle (or zenith angular distance), the angle between a direction of interest (e.g. a star) and the local zenith - that is, the complement of the
The Sun reaches the observer's zenith when it is 90° above the horizon, and this only happens between the
At a given location during the course of a day, the Sun reaches not only its zenith but also its
In
A zenith telescope is a type of telescope designed to point straight up at or near the zenith, and used for precision measurement of star positions, to simplify telescope construction, or both. The NASA Orbital Debris Observatory and the Large Zenith Telescope are both zenith telescopes, since the use of liquid mirrors meant these telescopes could only point straight up.
On the International Space Station, zenith and nadir are used instead of up and down, referring to directions within and around the station, relative to the earth.
Zenith star
Zenith stars (also "star on top", "overhead star", "latitude star")[7] are stars which culminate (pass) through the zenith. Used in celestial navigation it allowed the navigator to determine their latitudal position, since at every latitude different stars pass one's zenith, or with other words lie on the great circle of the zenith ("zenith circle"). Zenith stars are not to be confused with "steering stars"[7] of a sidereal compass rose of a sidereal compass.
See also
- Azimuth
- Geodesy
- History of geodesy
- Horizon zenith angle
- Keyhole problem
- Subsolar point
- Vertical deflection
- Horizontal coordinate system
- Analemma
References
- ISBN 978-0-521-15255-6.
- ISBN 978-8-42492-364-8.)
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: CS1 maint: location missing publisher (link - ^ "zenith". Dictionary.com Unabridged (Online). n.d. Retrieved 2012-03-21.
- ^ "Zenith". Merriam-Webster. Retrieved March 21, 2012.
- ^ van Gent, Robert Harry (2017). "Determining the Sacred Direction of Islam". Webpages on the History of Astronomy.
- ^ Khalid, Tuqa (2016). "Sun will align directly over Kaaba, Islam's holiest shrine, on Friday". CNN.
- ^ a b Lewis, David (1972). "We, the navigators : the ancient art of landfinding in the Pacific". Australian National University Press. Retrieved 2023-06-01.
Literature
- Glickman, Todd S. (2000). Glossary of meteorology. ISBN 978-1-878220-34-9.
- McIntosh, D. H. (1972). Meteorological Glossary (5th ed.). Chemical. ISBN 978-0-8206-0228-8.
- Picoche, Jacqueline (2002). Dictionnaire étymologique du français. Paris: ISBN 978-2-85036-458-7.