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: 88
key
  کلید   
kelid (#)

Fr.: clé   

A usually metal instrument used to operate a lock's mechanism.

M.E. key(e), kay(e), O.E. cæg "key," of unknown origin,

Kelid, variants (Tabari) kali, (Lori) kelil, (Laki) kalil "key; lock," (Kurd) kilil, kolun "latch, bolt;" Mid.Pers. kilêl "key." See also → include.

keyhole
  سوراخ ِ کلید   
surâx-e kelid (#)

Fr.: trou de serrure   

1) The hole in which a key of a lock is inserted.
2) → Keyhole Nebula.
3) A small, about 600 m wide, region of space close to the Earth where the Earth's gravity would perturb the trajectory of a passing → Near-Earth Object. The object will receive a gravitational push that will bring it back for a collision in the future. Also called resonance keyhole.

key; → hole.

Keyhole Nebula
  میغ ِ سوراخ ِ کلید   
miq-e surâx-e kelid

Fr.: Nébuleuse du Trou de Serrure   

A relatively small and dark cloud of molecules and dust seen silhouetted against the much brighter → Carina Nebula. It contains bright filaments of emitting hot gas and is roughly 7 → light-years in size.

keyhole; → nebula. The name was given by the English astronomer Sir John Herschel in the 19th century, because of the appearance of the nebula in low-resolution telescopes of that epoch.

Killing vector
  بردار ِ کیلینگ   
bordâr-e Killing

Fr.: vecteur de Killing   

A → vector field on a → Riemannian manifold (or → pseudo-Riemannian manifold) that preserves the → metric. In other words, the → derivative of the metric with respect to this vector field is null.

Named after the German mathematician Wilhelm Killing (1847-1923); → vector.

kilo-
  کیلو-   
kilo- (#)

Fr.: kilo-   

A prefix meaning 103.

Introduced in France in 1795, when the → metric system was officially adopted, from Gk. khilioi "thousand," of unknown origin.

kilogram (kg)
  کیلوگرم   
kilogram (#)

Fr.: kilogramme   

1) The basic unit of mass in the → International System of Units (SI) and → MKS versions of the → metric system, equal to 1,000 → grams. The kilogram is defined as the mass of the standard kilogram, a platinum-iridium bar kept at the International Bureau of Weights and Measures (BIPM), at Sèvre, near Paris, France. Copies of this bar are kept by the standards agencies of all the major industrial nations. A kilogram is very nearly equal to the mass of 1,000 cubic cm of water.
2) A unit of force; see → kilogram-force.

kilo-; → gram.

kilogram-force (kgf)
  کیلوگرم-نیرو   
kilogram-niru (#)

Fr.: kilogramme-force   

A unit of force equal to the force that produces an → acceleration of 9.80665 meters per second per second (m s-2) when acting on a mass of one kilogram.

kilogram; → force.

kilohertz (kHz)
  کیلوهرتز   
kilohertz (#)

Fr.: kilohertz   

A unit of → frequency, equal to 103 Hz.

kilo-; → hertz.

kilometer (km)
  کیلومتر   
kilometr (#)

Fr.: kilomètre   

A unit of length, equal to 1000 meters.,

kilo-; → meter.

kiloparsec (kpc)
  کیلوپارسک   
kilopârsek (#)

Fr.: kiloparsec   

A unit of distance equal to 1,000 → parsec (pc)s, or 3,260 → light-years.

kilo-; → parsec.

kilowatt-hour (kWh)
  کیلووات-ساعت   
kilowatt-sâ'at (#)

Fr.: kilowatt-heure   

A unit of energy equivalent to one kilowatt (1 kW) of power expended for one hour (1 h) of time. The kilowatt-hour is not a standard unit in any formal system, but it is commonly used to measure the consumption of electrical energy. To convert to → joules, use: 1 kWh = 3.6 × 106 J = 3.6 × 1013ergs.

kilo-; → watt-hour.

kinematic
  جنبشی، جنبشیک   
jonbeši, jonbešk

Fr.: cinématique   

Of or relating to → kinematics. Same as kinematical.

kinematics.

kinematic bias
  ورک ِ جنبشی   
varak-e jonbeši

Fr.: biais cinématique   

A systematic error introduced in a sample of stellar → proper motion data by higher velocity stars that are easier to measure.

kinematic; → bias.

kinematic viscosity
  وشکسانی ِ جنبشیک   
vošksâni-ye jonbešik

Fr.: viscosité cinématique   

The ratio of the → dynamic viscosity (η) to the density (ρ) of a fluid: ν = η/ρ. The unit of kinematic viscosity in the → SI system is m2s-1. In the → cgs system, cm2s-1, equal to 10-4 m2s-1, is called the → stokes (st).

kinematic; → viscosity.

kinematical
  جنبشی، جنبشیک   
jonbeši, jonbešik

Fr.: cinématique   

Of or relating to → kinematics. → kinematic.

kinematic; → -al.

kinematically decoupled core (KDC)
  مغزه‌ی ِ جنبشیکانه واجفسریده   
maqze-ye jonbešikâné vâjafsaridé

Fr.: cœur cinématiquement découplé   

A central, tightly bound stellar subsystem observed in some elliptical galaxies which rotates in the opposite direction with respect to the main body of the → elliptical galaxy. Elliptical galaxies are thought to be the result of the → merger of two or more sizable galaxies. A plausible scenario for how counter-rotating cores could form in such a merger is as follows. If at least one of the galaxies has a core region that is fairly tightly bound by the galaxy's gravity, and the direction in which the two galaxies orbit each other before merging is opposite to the direction of rotation of stars in that tightly bound core, it is likely that, after the merger, the tightly bound core will end up as the core of the new, larger galaxy, while retaining its original sense of rotation. The surrounding stars, on the other hand, will rotate in a different way dictated by the orbital motion of the galaxies around each other, before the merger. While this is a plausible scenario, it can only explain some of the counter-rotating cores. Recently A. Tsatsi et al. (2015, ApJ 802, L3) have shown that although the two → progenitor galaxies are initially following a → prograde orbit, strong reactive forces during the merger can cause a short-lived change of their orbital spin; the two progenitors follow a → retrograde orbit right before their final coalescence. This results in a central kinematic decoupling and the formation of a large-scale (~2 kpc radius) counter-rotating core at the center of the final elliptical-like merger remnant, while its outer parts keep the rotation direction of the initial orbital spin.

kinematical; → decouple; → core.

kinematics
  جنبشیک   
jonbešik

Fr.: cinématique   

The branch of mechanics dealing with the description of the motion of bodies or fluids without reference to the forces producing the motion.

From Gk. kinetikos "moving, putting in motion," from kinetos "moved," verbal adj. of kinein "to move;" PIE base *kei- "to move to and fro" (cf. Mod.Pers. šodan, šow- "to go; to become;" Av. šiyav-, š(ii)auu- "to move, go," šiyavati "goes," šyaoθna- "activity; action; doing, working;" O.Pers. šiyav- "to go forth, set," ašiyavam "I set forth;" Skt. cyu- "to move to and fro, shake about; to stir," cyávate "stirs himself, goes;" Goth. haitan "call, be called;" O.E. hatan "command, call").

Jonbešik, from jonbeš "motion" + -ik-ics. The first element from Mid.Pers. jumbidan, jumb- "to move," Lori, Laki jem "motion," related to gâm "step, pace;" O.Pers. gam- "to come; to go," Av. gam- "to come; to go," jamaiti "goes," gāman- "step, pace" (Mod.Pers. âmadan "to come"); Skt. gamati "goes;" Gk. bainein "to go, walk, step," L. venire "to come;" Tocharian A käm- "to come;" O.H.G. queman "to come;" E. come; PIE root *gwem- "to go, come."

kinetic
  جنبشی   
jonbeši (#)

Fr.: cinétique   

Of or relating to motion; caused by motion; characterized by movement.

From Gk. kinetikos "moving, putting in motion," from kinein "to move," → kinematics.

Jonbeši, adj. of jonbeš, verbal noun of jonbidan, → move.

kinetic energy
  کاروژ ِ جنبشی   
kâruž-e jonbeši

Fr.: énergie cinétique   

The energy which a body possesses as a consequence of its motion, defined as one-half the product of its mass m and the square of its speed v, i.e. 1/2 mv2.

kinetic; → energy.

kinetic helicity
  پیچاری ِ جنبشی   
picari-ye jonbeši

Fr.: hélicité cinétique   

In fluid mechanics, a quantity that describes helical flow. It is defined by the integrated scalar product of the velocity field and the → vorticity: KK = ∫ dVu . ( x u). In the absence of magnetic field, this quantity is conserved by the → Euler equation. See also → magnetic helicity.

kinetic; → helicity.

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