Meteo.: A weather phenomenon associated with atmospheric high pressure. In the Northern Hemisphere an anticyclone rotates in the clockwise direction. The rotation is caused by the movement of colder higher pressure air that is moving away from the poles toward the equator being affected by the rotation of the Earth.
Having a sense of rotation about the local vertical opposite to that of the Earth's rotation. In other words, → clockwise in the Northern Hemisphere, → counterclockwise in the Southern Hemisphere, and undefined at the equator. The opposite of → cyclonic (Meteorology Glossary, American Meteorological Society).
→ anticyclone; → -ic.
1) falak-e tadvir (#); 2) apicarxé
1) In → Ptolemaic system, a circular
→ orbit of a body around a point that itself
orbits circularly another point. Such a system was formulated to explain some
orbits in terms of → circular
motions in a → geocentric
1) Falak-e tadvir, from Ar. falak al-tadwir, from falak
"sphere" + tadwir "causing to turn in a circle."
Of or pertaining to an → epicycle.
Fr.: fréquence épicyclique
In the → epicyclic theory of Galactic rotation, the frequency at which a star in the → Galactic disk describes an ellipse around its mean circular orbit. The epicyclic frequency relates to the → Oort's constants. In the solar neighborhood the epicyclic frequency is about 32 km s-1 kpc-1.
Fr.: oscillation épicyclique
In a → disk galaxy, the motion of a star about the orbital → guiding center when it is displaced radially. See also → epicyclic frequency, → epicyclic theory.
→ epicyclic; → oscillation.
Fr.: théorie épicyclique
The theory that describes the Galactic dynamics, that is the orbits of stars and gas clouds in the → Galactic disk, as well as the spiral → density wave. Formulated by Bertil Lindblad (1895-1965), the epicyclic theory assumes that orbits are circular with small deviations. Star orbits are described by the superposition of two motions: i) a rotation of the star (epicenter) around the Galactic center at the circular angular velocity, Ω, and ii) a retrograde elliptical motion at → epicyclic frequency, κ. The epicyclic motion in the Galactic plane occurs in a retrograde sense to conserve → angular momentum. In general Ω and κ are different and, therefore, orbits do not close. However, seen by an observer who rotates with the epicenter, orbits are closed ellipses.
A curve traced by a point of a circle that rolls on the outside of a fixed circle. This curve was described by the Gk. mathematicians and astronomer Hipparchus, who made use of it to account for the apparent movement of many of the heavenly bodies.
Fr.: glacé, glacial
Made of, covered with, or containing → ice.
→ ice + an English suffix of adjectives denoting "characterized by or inclined to."
JUpiter ICy moons Explorer (JUICE)
Puyešgar-e Mânghâ-ye Yaxi-ye Hormoz
Fr.: Jupiter ICy moons Explorer
An interplanetary mission currently in development by the → European Space Agency planned for launch in 2020. It is aimed mainly at in-depth studies of three potentially ocean-bearing satellites, → Ganymede, → Europa, and → Callisto. JUICE will complete a unique tour of the Jupiter system including several flybys of each planet-sized world, culminating with orbit insertion around Ganymede, the largest moon in the Solar System, followed by nine months of operations in its orbit. JUICE will carry the most powerful scientific payload ever flown to the outer Solar System. It consists of 10 state-of-the-art instruments plus one experiment that uses the spacecraft telecommunication system with ground-based instruments.
The point in the orbit of a satellite around the Moon closest to the Moon; opposite of → apocynthion.
→ peri- + Gk. Cynthia "goddess of the Moon;" → Cynthian.
Fr.: 1) ligne d'action; 2) politique
1) A definite course of action adopted for the sake of expediency, facility, etc.
M.E. policie "government, civil administration," from O.Fr. policie "political organization, civil administration," from L.L. politia "the state, civil administration," from Gk. politeia "state, administration, government, citizenship," from polites "citizen," from polis "city, state."
Kârâh, contraction of kâr râh, or râh-e kâr literally "way of doing, ~ ~ action," from râh, → way, + kâr "doing, action, → work."
Fr.: responsable politique, décideur
A person responsible for making policy, especially in government (Dictionary.com).