An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 155 Search : ratio
 elliptic aberration   بیراهش ِ بیضی‌گون   birâheš-e biyzigunFr.: aberration elliptique   That part of → annual aberration proportional to the → eccentricity of the Earth's orbit.→ elliptic; → aberration. emigration   زموژش   zomužešFr.: émigration   An act or instance of emigrating; a body of emigrants; emigrants collectively.Verbal noun of → emigrate. energy generation equation   هموگش ِ آزانش ِ کاروژ   hamugeš-e âzâneš-e kâružFr.: équation de génération d'énergie   Of a stellar → nuclear fusion, the equation describing the → energy generation rate as a function of → density and → temperature.→ energy; → generation; → equation. energy generation rate   نرخ ِ آزانش ِ کاروژ   nerx-e âzâneš-e kâružFr.: taux de génération d'énergie   Of a stellar → nuclear fusion, the energy produced per unit mass per unit time, usually denoted ε (erg g-1s-1). The general form of the energy generation equation is: ε = ε0ρλTν, where ε0, ρ, and λ are constants over some efficiently restricted range of → temperature T, → density ρ, and → chemical composition. The temperature exponent ν is about 4, 15, and 40 for → proton-proton chain, → CNO cycle, and → triple alpha process, respectively.→ energy; → generation; → rate. evaporation   بخارش   boxârešFr.: évaporation   The physical process by which a liquid is transformed to the gaseous state, usually by means of heat; the opposite of → condensation. Also called vaporization.From L. evaporationem (nom. evaporatio), from evaporare "to disperse in vapor," from → ex- "out" + → vapor "steam."Boxârš, verbal noun of boxâridan "to evaporate," from boxâr, → vapor. exploration   پویش   puyeš (#)Fr.: exploration   1) An act or instance of exploring or investigating; examination. 2. The investigation of unknown regions. 3) The process of searching for minerals by means of geological studies. 4) Medicine: An examination or investigation for diagnostic purposes, usually involving endoscopy or a surgical procedure.Verbal noun of → explore. extreme mass ratio inspiral (EMRI)   فروپیچه با وابر ِ استوم ِ جرم   forupicé bâ vâbar-e ostom-e jermFr.: orbite plongeante d'un trou noir binaire, au rapport de masse extrême   A compact stellar remnant (e.g., a → white dwarf, → neutron star, or → black hole) that undergoes → inspiral into a much more massive object (→ supermassive black hole found → galactic centers). EMRIs are potential sources of low-frequency → gravitational waves. Predictions of the EMRI event rates span a wide range, from ~ 10-9 to 10-6 yr-1 per galaxy (Merritt et al. 2011, Physical Review D 84, 044024). See also → resonant relaxation.→ extreme; → mass; → ratio; → inspiral. federation   هیاوش   hiâyvešFr.: fédération   1) The act of federating or uniting in a league. 2) A political unit formed from smaller units on a → federal basis.Verbal noun of → federate. flux calibration   کبیزش ِ شار   kabizeš-e šârrFr.: calibration de flux   The → calibration of the flux received by a detector in terms of absolute units.→ flux; → calibration. focal ratio   وابر ِ کانونی   vâbar-e kânuniFr.: rapport focal   The ratio of the → focal length of a reflecting surface or lens to its effective diameter, i.e. to its → aperture. The smaller the focal ratio, the smaller the image scale and the more luminous the image for a given aperture.→ focal; → ratio. gas-to-dust ratio   وابر ِ گاز به غبار   vâbar-e gâz bé qobârFr.: rapport gaz/poussière   The mass ratio of gas to dust. It amounts to approximately 100 in the → interstellar medium, but may vary in → molecular clouds and → circumstellar disks due to dust → grain evaporation, → dust settling, → condensation of gas, etc. The gas-to-dust ratio depends on the → metallicity. It is larger in galaxies with lower metallicity.→ gas; → dust; → ratio. generation   آزانش   âzânešFr.: génération   1) A coming into being. 2) The → production of → energy (→ heat or → electricity).Verbal noun of → generate. geometrical libration   رخگرد ِ هندسی   roxgard-e hendesi (#)Fr.: libration géométrique   Libration resulting from changes in the location of the observer with respect to body. More specifically, a lunar libration motion that results from the Earth based observer seeing the Moon from different directions at different times. There are three types of geometrical libration: → libration in longitude, → libration in latitude, and → diurnal libration. See also → physical libration.→ geometric; → libration. golden ratio   وابر ِ زرین   vâbar-e zarrinFr.: nombre d'or   If a line segment is divided into a larger subsegment (a) and a smaller subsegment (b), when the larger subsegment is related to the smaller exactly as the whole segment is related to the larger segment, i.e. a/b = (a + b)/a. The golden ratio, a/b is usually represented by the Greek letter φ. It is also known as the divine ratio, the golden mean, the → golden number, and the golden section. Its numerical value, given by the positive solution of the equation φ2 - φ - 1 = 0, is approximately 1.618033989. The golden ratio is closely related to the → Fibonacci sequence.→ golden; → ratio. grain evaporation   بخارش ِ دانه   boxâreš-e dânéFr.: évaporation des grains   Conversion of dust grains into smaller grains due to high environmental temperatures.→ grain; → evaporation. gravitational acceleration   شتاب ِ گرانشی   šetâb-e gerâneši (#)Fr.: accélération gravitationnelle   The acceleration caused by the force of gravity. At the Earth's surface it is determined by the distance of the object form the center of the Earth: g = GM/R2, where G is the → gravitational constant, and M and R are the Earth's mass and radius respectively. It is approximately equal to 9.8 m s-2. The value varies slightly with latitude and elevation. Also known as the → acceleration of gravity. helium-argon calibration   کبیزش ِ هلیوم-آرگون   kabizeš-e heliyom-ârgonFr.: calibration hélium-argon   A wavelength calibration of astronomical spectra using a helium-argon light source.→ helium; → argon; → calibration. HESS collaboration   همکاری ِ HESS   hamkâri-ye HESSFr.: collaboration HESS hydration   هیدرش، آبش   hidreš, âbeš (#)Fr.: hydratation   The process of combining with → water.Verbal noun of → hydrate. image restoration   بازسازی ِ تصویر   bâzsâzi-ye tasvir (#)Fr.: restauration d'image   The process by virtue of which the original image can be created by removing the blurring and the noise that occur during image formation.→ image; → restoration.