An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < "no abs acc ads amb ann arg ato B-m bla bro cat Che co- col com com con con con cor cro dec def dep dif dil dis dis dur eje emi equ evo exp fab fis fra fus geo gra gra har Huy ima ind inf ins int int ion jum law lin low mag mat mic Moo nec non nuc obs opp Ori par per per phy ple pop pre pro pro pul rad rad Ray rec reg rep Ric rot Sch sec Sha soc spe sta ste sub syn the tot tri uni Ven vis wor > >>

Number of Results: 1965 Search : ion
argument of perihelion
  آروزمان ِ پیراهور   
âruzmân-e pirâhur

Fr.: argument du périhélie   

The angular distance between the → ascending node of an object orbiting the Sun and its perihelion. Argument of perihelion is measured in the → orbital plane with respect to the Sun and in the direction of motion. It is one of the → orbital elements and usually shown with the symbol ω. See also: → argument of perigee, → argument of periapsis.

argument; → perihelion.

argumentation
  آروزش   
âruzeš

Fr.: argumentation   

The presentation and elaboration of an argument or arguments.

Noun from → argument.

arithmetic progression
  فرایازی ِ حسابی   
farâyâzi-yz hesâbi (#)

Fr.: progression arithmétique   

A → sequence of n numbers or quantities such that the difference between any two successive terms is a constant. In particular, if a is the first term, the nth term is a + (n - 1)d, where d is the constant. Also called → arithmetic sequence.

arithmetic; → progression.

Arrhenius equation
  هموگش ِ آرنیوس   
hamugeš-e Arrhenius

Fr.: équation d'Arrhenius   

An important relationship in physical chemistry that combines the concepts of → activation energy and the → Maxwell-Boltzmann distribution law. It is expressed by: k = Ae-Ea/(RT), where k is the chemical → reaction rate, Ea is the activation energy, R is the → gas constant, and T is → temperature.

Named for Svante Arrhenius (1859-1927), Swedish chemist and physicist who suggested the relationship in 1889.

ascension
  فرازش   
farâzeš

Fr.: ascension   

The act of ascending; ascent.

Verbal noun of → ascend; → -tion.

assertion
  ستوارش   
sotvâreš

Fr.: affirmation   

The act of asserting or something that is asserted.

assert; → -tion.

assignation
  نشارش   
nešâreš

Fr.: rendez-vous, attribution   

1) An appointment for a meeting.
2) The act of assigning; → assignment (Dictionary.com).

Verbal noun of → assign.

association
  آهزش؛ انجمن   
âhazeš; anjoman (#)

Fr.: association   

1) The act of associating, → associate; the state of being associated.
2) A group of → astronomical objects physically or apparently gathered in a particular area of sky, for example an → stellar association.
3) An organization of persons having a common interest. → dissociation.

Association, noun from → associate.

Âhazeš, verbal noun of → âhazidanassociate. Anjoman, for the meaning 3, from Mid.Pers. anjaman, from Av. han-jamana, from han- "together" + jamana, from gam- "to come;" cf. Skt. samgamana "gathering together."

association member
  هموند ِ آهزش   
hamvand-e âhazeš

Fr.: membre d'une association   

A celestial body making part of an astronomical association.

association; → member.

assumption
  آگرب، فرض   
âgarb, farz (#)

Fr.: supposition   

A fact or statement (as a proposition, axiom, postulate, or notion) taken for granted.

M.E., from L.L. assumption, assumptio "taking up," from L. assumere, → assume.

Âgarb, from â-, nuance prefix, + garb, from Av./O.Pers. grab-, Av. gərəb- "to take, to seize;" cf. Mod.Pers. gereftan "to take; to assume;" Skt. grah-, grabh- "to seize, to take," graha "seizing, holding, perceiving;" M.L.G. grabben "to grab;" E. grab "to take or grasp suddenly;" PIE *ghrebh- "to seize."
Ar. farz "assumption, hypothesis."

asteroid designation
  نامگزینی ِ سیارک   
nâmgozini-ye sayyârak

Fr.: désignation des astéroïdes   

1) For an asteroid whose orbit is precisely known, a number and optionally a proper name, e.g. (7) Iris, (24101) Cassini, (99942) Apophis.
2) For an asteroid whose orbit is not known, a provisional designation composed of four elements: number.letter.letter.(optionally)number. The first number indicates the year of discovery. The first letter denotes the half-month of the discovery (A: first half of January, Y: second half of December; the letter "I" is excluded). The second letter and the following number indicate the order of discovery within the half-month. For example, the first asteroid discovered in the first half of May 1960 is: 1960 JA. Since more than 25 objects (without "I") might be detected within a half-month, the number following the second letter indicates the number of 25 discoveries. Hence, 2001 SD3 was discovered in the second half of September 2001 and was the (D =) 4 + (25 x 3) or the 79th object found during that period.

asteroid; → designation.

astration
  ستارش   
setâreš

Fr.: astration   

The cyclic process in which interstellar matter is incorporated into newly formed stars, where it undergoes nuclear processing, is thus enriched with heavier elements, and then returns into the interstellar medium through supernova explosion or stellar winds to be used in the formation of a newer generation of stars.

Astration, from astrate, from astr-, → astro-, + noun-forming suffix -ation.

Setâreš, from setâridan (from setâré "star" + verb-making suffix -idan) + noun-builder -eš.

astronomical refraction
  شکست ِ اخترشناختی   
šekast-e axtaršenâxti

Fr.: réfraction astronomique   

The → angular → displacement of a point on the → celestial sphere due to the Earth's → atmospheric refraction.

astronomical; → refraction.

atmospheric absorption
  درشم ِ جوی   
daršam-e javvi

Fr.: absorption atmosphérique   

The absorption of → electromagnetic radiation in the → atmosphere mainly by → water vapor, → carbon dioxide, and oxygen. The atmosphere introduces two more limiting factors in → remote sensing: → atmospheric scattering and → atmospheric turbulence.

atmospheric; → absorption.

atmospheric circulation
  پرهونش ِ هواسپهری   
parhuneš-e havâsepehri

Fr.: circulation atmosphérique   

The large-scale movements of air around areas of high and low pressure whereby heat is distributed on the surface of the Earth. Atmospheric motion is driven by uneven heating of the planet. The atmosphere (and ocean) → transfers the excess heat from → tropics to → poles. The flow is determined by balance between → pressure gradients and the → Coriolis effect.

atmospheric; → circulation.

atmospheric dispersion
  پاشش ِ جوی   
pâšeš-e javvi

Fr.: dispersion atmosphérique   

The splitting of starlight into a spectrum in the atmosphere because the atmosphere acts as a refracting prism. This phenomenon brings about a practical problem for spectroscopic observations using a slit. → differential refraction; → atmospheric refraction.

atmospheric; → dispersion.

atmospheric emission
  گسیل ِ جوی   
gosil-e javvi

Fr.: émission atmosphérique   

The emission of electromagnetic radiation from the atmosphere due to thermal and → non-thermal processes. → Thermal emission comes mainly from → water vapor. Non-thermal processes result in emission lines oxygen (optical) and OH (near-IR). Atmospheric emission is a very significant source of noise in astronomical observations. See also → airglow, → aurora.

atmospheric; → emission.

atmospheric extinction
  خاموشی ِ جوی   
xâmuši-ye javvi

Fr.: extinction atmosphérique   

The decrease in the intensity of light from a celestial body due to absorption and scattering by Earth's atmosphere. It increases from the zenith to the horizon and affects short wavelengths more than long wavelengths, so that objects near the horizon appear redder than they do at the zenith.

atmospheric; → extinction.

atmospheric refraction
  شکست ِ جوی   
šekast-e javvi

Fr.: réfraction atmosphérique   

The shift in apparent direction of a celestial object caused by the bending of light while passing through the Earth's atmosphere. Since the density of the atmosphere decreases with altitude, the starlight will bend more as it continues down through the atmosphere. As a result, a star will appear higher in the sky than its true direction.

atmospheric; → refraction.

atomic diffusion
  پخش ِ اتمی   
paxš-e atomi

Fr.: diffusion atomique   

element diffusion.

atomic; → diffusion.

<< < "no abs acc ads amb ann arg ato B-m bla bro cat Che co- col com com con con con cor cro dec def dep dif dil dis dis dur eje emi equ evo exp fab fis fra fus geo gra gra har Huy ima ind inf ins int int ion jum law lin low mag mat mic Moo nec non nuc obs opp Ori par per per phy ple pop pre pro pro pul rad rad Ray rec reg rep Ric rot Sch sec Sha soc spe sta ste sub syn the tot tri uni Ven vis wor > >>