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.
Infrared Astronomical Satellite (IRAS)
mâhvâre-ye axtaršenâxti-e forusorx (#)
Fr.: satellite astronomique infrarouge
An orbiting infrared telescope (60 cm mirror) which successfully operated from launch in January 1983 until the supply of coolant ran out in November 1983. It was a collaborative mission between NASA, the Netherlands, and the UK, and mapped 95% of the whole sky in the wavelength bands 12, 25, 60, and 100 microns.
International Astronomical Union (IAU)
Yekâyeš-e Jahâni-ye Axtaršenâsi
Fr.: Union Astronomique Internationale (UAI)
An astronomical association of astronomers that is the controlling body of world astronomy. It was founded in Brussels in 1919.
Strasbourg Astronomical Data Center (CDS)
Fr.: Centre de Données astronomiques de Strasbourg (CDS)
A data center dedicated to the collection and worldwide distribution of astronomical data and related information. It is located at the Strasbourg Astronomical Observatory, France. The CDS has several goals, mainly: collecting all of the useful information regarding astronomical objects in computerized form, including observational data produced by observatories on the ground or in space; upgrading these data by critical evaluations and comparisons; and distributing the results to the astronomical community. Currently the CDS services include: → SIMBAD, Aladin interactive sky atlas, and VizieR catalogues.
CDS, short for Centre de Données astronomiques de Strasbourg.