nimruzân-e âsmâni (#)
Fr.: méridien céleste
Fr.: méridien des éphémérides
A fictitious meridian that rotates independently of the Earth at the uniform rate implicitly defined by → Terrestrial Dynamical Time (TDT).
Fr.: méridien géodésique
Fr.: méridien de Greenwich
A borough in southeast London, England, on the Thames River. It is the site of the original Royal Observatory, through which passes the prime meridian, or longitude 0°; → meridian.
Fr.: méridien local
The meridian through any particular place, serving as the reference for local time, in contrast to the Greenwich meridian.
Fr.: méridien magnétique
A meridian passing through the Earth's → magnetic poles.
1) Geography: An imaginary line on the Earth's surface joining the north and south
poles at right angles to the equator. See also
→ local meridian,
→ prime meridian.
M.E., from O.Fr. meridien, from L. meridianus "of noon, southern," from meridies "noon, south," from meridie "at noon," altered by dissimilation from *medi die, locative of medius "mid-" + dies "day."
Nimruzân, coined by Pers. astronomer (A.D. 973-1048) in his at-Tafhim, from nim "mid-, half" (Mid.Pers. nêm, nêmag "half;" Av. naēma- "half;" cf. Skt. néma- "half") + ruz, → day, + -ân suffix denoting time and place.
Fr.: angle horaire
Same as hour angle.
Fr.: circle méridien
A telescope with a graduated vertical scale, used to measure the declinations of heavenly bodies and sometimes to determine the time of meridian transits.
Fr.: instrument méridien
An instrument designed to observe objects when they cross the meridian.
Fr.: observation au méridien
The observation of a star when it crosses an observer's meridian.
Fr.: passage au méridien
The moment when a celestial object crosses an observer's meridian. Same as meridian transit.
Moon's prime meridian
nimruzân-e naxosti-ye Mâng
Fr.: méridien origine de la lune
The line connecting the Moon's north pole with its south pole, and passing through the center of the lunar disk. The longitude of the Moon's prime meridian is zero degrees.
Fr.: méridien origine
The meridian at which longitude is defined to be 0°. The meridian running through Greenwich.