An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 13 Search : close
close
  کیپ   
kip (#)

Fr.: serré   

Having little or no space between elements or parts, as in → close binary, → close approach; tight and compact.

M.E. clos, closed, from O.Fr., from L. clausus, p.p. of claudere "to close."

Kip "close, tight" in spoken Pers.

close approach
  نزدش ِ کیپ   
nazdeš-e kip

Fr.: approche serrée   

In astronomy a general term to describe the positions of two or more objects that come unusually near one to another. In particular, regarding an asteroid's position with respect to Earth, when it is within the Moon's orbit.

close; → approach.

close binary star
  ستاره‌ی ِ دورین ِ کیپ   
setâre-ye dorin-e kip

Fr.: étoile binaire serrée   

A binary system in which the separation of the component stars is comparable to their diameters, so that they influence each other's evolution most commonly by the tidal forces.

close; → binary; → star.

close binary system
  راژمان ِ دورین ِ کیپ   
râžmân-e dorin-e kip

Fr.: système binaire serré   

A → binary system in which the distance separating the stars is comparable to their size. Most close binaries are spectroscopic binaries (→ spectroscopic binary) and/or eclipsing binaries (→ eclipsing binary). In most of them → mass transfer occurs at some stage, an event which profoundly affects the → stellar evolution of the components. The evolution of close binaries depends on the → initial masses of the two stars and their → separation. When the more massive star evolves into a → red giant first, material will spill through the inner point onto its companion, thereby affecting its companion's evolution. Mass transfer can also alter the separation and → orbital period of the binary star.

close; → binary; → system.

close encounter
  رویارویی ِ کیپ   
ruyâruyi-ye kip

Fr.: rencontre proche   

1) In a → star cluster, coming across of two stars so closely that their → orbits alter by their mutual → gravitational attractions.
2) As regards an → asteroid or → comet, a situation when it crosses the Moon's orbit and approaches the Earth with a risk of collision. See also → close approach, → encounter.

close; → encounter.

closed
  بسته   
basté (#)

Fr.: fermé   

Having boundaries; limited. → closed curve; → closed Universe.

Closed, p.p. of close, from M.E. clos, from O.Fr., from clore "to shut," from L. clausus, p.p. of claudere "to close."

Basté p.p.of bastan, from Mid.Pers. bastan/vastan "to bind, shut," Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind, → band.

closed curve
  خم ِ بسته   
xam-e basté (#)

Fr.: courbe fermée   

A curve whose ends are joined.

closed; → curve.

closed space
  فضایِ بسته   
fazâ-ye basté (#)

Fr.: espace fermé   

A bounded space the surface of which has the property that if one travels in any direction upon it without changing direction, one will end up back to the departure point. An example is a sphere. Triangles which lie on the surface of a closed space will have a sum of angles which is greater than 180°. An closed space has a positive → curvature. See also → closed Universe, → open space.

closed; → space.

closed system
  راژمان ِ بسته   
râžmân-e basté

Fr.: système fermé   

Thermodynamics: A system which can exchange energy with the surroundings but not matter. → open system; → isolated system.

closed; → system.

closed Universe
  گیتی ِ بسته   
giti-ye basté (#)

Fr.: Univers fermé   

A → cosmological model, first formulated by Friedmann and Lemaître, in which the Universe has a → finite size and lifetime and → space has a → positive → curvature, e.g. a Universe with a density greater than the → critical density. See also → closed space.

closed; → Universe.

closed wff
   wff بسته   
wff basté

Fr.: FBF fermée   

In → predicate logic, a → wff with no → free occurrences of any → variable. Also called a → sentence.

closed; → wff.

massive close binary
  دورین ِ کیپ ِ پرجرم   
dorin-e kip-e porjerm

Fr.: binaire serrée massive   

A → close binary system composed of two → massive stars.

massive; → close binary star.

quasi-closed subsystem
  زیر-راژمان ِ چونان‌بسته   
zir-râžmân-e cunân-basté

Fr.: sous-système quasi-fermé   

A subsystem if its intrinsic energy is large, on the average, with respect to the energy of its interaction with other portions of the → closed system.

quasi-; → closed; → subsystem.