Fr.: binaire astrométrique
A binary star in which the presence of an unresolved companion is revealed by small oscillations in the movement of the visible component caused by the gravitational influence of the unseen component.
The precise measurement of the positions and motions of → astronomical objects.
Axtarsanji, from axtar, → astro-, + -sanji "measuring."
fazânavard (#), keyhânnavard (#)
Fr.: astronaute, cosmonaute
A person trained to pilot, navigate, or otherwise participate as a crew member of a spacecraft.
Astronaut, from Gk. → astro- "star" + nautes "sailor," from naus "ship" (cognate with Mod.Pers. nâv "ship;" Av./O.Pers. *nāv-, O.Pers. nāviyā- "fleet;" Skt. nau-, nava- "ship, boat;" Gk. naus, neus, L. navis; PIE *nāu- "ship").
Fazânavard, from Ar. fazâ "space" + navard agent
noun from navardidan "to travel, walk, pass by
fazânavardi (#), keyhânnavardi (#)
The science and technology of space flight, including the building and operation of space vehicles.
Axtaršenâs has a long history in Persian; it is abundantly used by Ferdowsi (A.D. 950-1020) in his great work Šâhnâmé (Shahnameh); from axtar "star" → astro- + šenâs contraction of šenâsandé "expert, knowlegeable, skilled," from šenâxtan "to know, to recognize." → astronomy.
axtaršenâxti, axtaršenâsik, axtari (#)
Of or relating to → astronomy.
Fr.: horloge astronomique
A precise pendulum clock with separate dials for seconds, minutes, and hours. It was originally used by astronomers to calculate astronomical time.
pâyâ-ye axtaršenâsik, ~ axtaršenâxti (#)
Fr.: constante astronomique
hamârâhâ-ye axtaršenâsik, ~ axtarsršnâxti (#)
Fr.: coordonnées astronomiques
Values in a reference system used to relate the position of a body on the celestial sphere.
Fr.: horizon astronomique
The intersection of a plane perpendicular to the radius of the Earth through the observer's eye with the celestial sphere. Same as → true horizon. Because the → celestial sphere has an infinite radius, two observers at different heights above sea level, but placed on the same vertical line, have the same astronomical horizon. Because of → dip of the horizon, the astronomical horizon always lies above the → sea horizon. But on land it is usually hidden by trees, hills, and buildings which determine the observer's → apparent horizon.
Fr.: instrument astronomique
A device used to observe and study → astronomical objects.
Fr.: latitude astronomique
barâxt-e axtaršenâsik, ~ axtari
Fr.: objet astronomique
A naturally occurring physical entity or association that lies beyond the Earth's atmosphere and can be studied observationally. In other words, a gravitationally bound structure that is associated with a position in space, but may consist of multiple independent astronomical objects. A list of astronomical objects includes → planets, → asteroids, → comets, → stars, → nebulae, galaxies (→ galaxy), → galaxy clusters, → pulsars, and → black holes. Note that → celestial body, → celestial object, and → heavenly body are less technical terms for these entities.
nepâhesgâh-e axtaršenâsik, ~ axtaršenâxti
Fr.: observatoire astronomique
A building, place, or institution designed and equipped for making → observations of astronomical phenomena.
Fr.: réfraction astronomique
sit-e axtaršenâsik, ~ axtaršenâxti
Fr.: site astronomique
A certain place whose characteristics, as to location, altitude, atmospheric conditions, etc., make it appropriate for astronomical observations.
Fr.: table astronomique
One of a set of tables giving parameters used for calculations of positions of the Sun, the Moon, and the planets in particular in pre-telescopic astronomy. The oldest known astronomical tables are those of Ptolemy. In Modern astronomy it is usually replaced by the term → ephemeris. Same as → zij. See also → Toledan Tables, → Alfonsine Tables.
nimtâb-e axtaršenâsik, ~ axtarsnâxti
Fr.: crépuscule astronomique
The time between sunset or sunrise and the moment when the Sun's center lies 18° below the horizon. → civil twilight.
astronomical unit (au)
yekâ-ye axtaršenâsik, ~ axtaršenâxti (#)
Fr.: unité astronomique
1) A unit of length equal to 149 597 870 700 m exactly, with symbol "au"
(re-definition at the International Astronomical Union's 28th General
Assembly in Beijing, China, August 20-31). The astronomical unit equals
1.5813 × 10-5 → light-years and
4.8481 ×10-6 → parsecs.
The science of the celestial bodies and the Universe, dealing especially with the positions, dimensions, distribution, motion, chemical composition, energy, and evolution of celestial bodies and phenomena.
O.Fr. astronomie, from L. astronomia, from Gk. astronomia, from → astro- "star" + nomos "arranging, regulating," related to nemein "to deal out."
Axtaršenâsi, from axtar "star," → astro- + -šenâsi "knowledge" from šenâxtan "to know, to discern."