An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 13 Search : meridian
celestial meridian
  نیمروزان ِ آسمانی   
nimruzân-e âsmâni (#)

Fr.: méridien céleste   

The great circle on the → celestial sphere, passing through the two → celestial poles and the observer's → zenith.

celestial; → meridian.

ephemeris meridian
  نیمروزان ِ روزیجی   
nimruzân-e ruziji

Fr.: méridien des éphémérides   

A fictitious meridian that rotates independently of the Earth at the uniform rate implicitly defined by → Terrestrial Dynamical Time (TDT).

ephemeris; → meridian.

geodetic meridian
  نیمروزان ِ زمین‌سنجیک   
nimruzân-e zamin-sanjik

Fr.: méridien géodésique   

The → ellipse through the point in question which passes through the → geodetic poles.

geodetic; → meridian.

Greenwich Meridian
  نیمروزان ِ گرینویچ   
nimruzân-e Greenwich

Fr.: méridien de Greenwich   

The → prime meridian that separates east from west in the same way that the Equator separates north from south. It is defined by the position of the → Airy transit circle.

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.

local meridian
  نیمروزان ِ محلی   
nimruzân-e mahali

Fr.: méridien local   

The meridian through any particular place, serving as the reference for local time, in contrast to the Greenwich meridian.

local; → meridian.

magnetic meridian
  نیمروزان ِ مغناتیسی   
nimruzân-e meqnâtisi

Fr.: méridien magnétique   

A meridian passing through the Earth's → magnetic poles.

magnetic; → meridian.

meridian
  نیمروزان   
nimruzân (#)

Fr.: méridien   

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.
2) Astron.: An imaginary great circle on the → celestial sphere that passes through its poles and the observer's → zenith.

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.

meridian angle
  زاویه‌ی ِ نیمروزان   
zâviye-ye nimruzân

Fr.: angle horaire   

Same as hour angle.

meridian; → angle.

meridian circle
  پرهون ِ نیمروزانی   
parhun-e nimruzâni

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.

meridian; → circle.

meridian instrument
  سازال ِ نیمروزانی   
sâzâl-e nimruzâni

Fr.: instrument méridien   

An instrument designed to observe objects when they cross the meridian.

meridian; → observation.

meridian observation
  نپاهش ِ نیمروزانی   
nepâheš-e nimruzâni

Fr.: observation au méridien   

The observation of a star when it crosses an observer's meridian.

meridian; → observation.

meridian passage
  گذر ِ نیمروزانی   
gozar-e nimruzâni

Fr.: passage au méridien   

The moment when a celestial object crosses an observer's meridian. Same as meridian transit.

meridian; → passage.

prime meridian
  نیمروزان ِ نخستی   
nimruzân-e noxosti

Fr.: méridien origine   

The meridian at which longitude is defined to be 0°. The meridian running through Greenwich.

primary; → meridian.