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: 152 Search : ten
2062 Aten
  آتن   
2062 Aten

Fr.: 2062 Aten   

The first → asteroid found to have an orbital → semi-major axis of less than one → astronomical unit. Discovered by the American woman astronomer Eleanor F. Helin (1932-2009) in 1982, it is the prototype of the → Aten asteroids.

Named after Aten, the Egyptian god of the solar disk.

absolute tensor
  تانسور ِ اوست   
tânsor-e avast

Fr.: tenseur absolu   

A → tensor of → weight  → zero.

absolute; → tensor.

antenna
  آنتن   
ânten

Fr.: antenne   

1) General: A device or a set of wires that receives or sends out radio signals.
2) In radio astronomy, the major dish-like component or wired structure used to collect radio signals.

L. antenna "sail yard," the long yard that sticks up on some sails, of unknown origin, perhaps from PIE base *temp- "to stretch, extend." In this sense, it is a translation of Gk. keraiai "horns" (of insects).

Âten, from Fr. antenne, from L. as above.

antenna gain
  بهره‌ی ِ آنتن   
bahre-ye ânten

Fr.: gain d'antenne   

A measure of the directivity of a radio telescope. It is the ratio of the amount of power received in the direction the dish is pointing to the smaller amount of power from other directions in the sidelobes.

antenna; → gain.

antenna lobe
  لپ ِ آنتن   
lap-e ânten

Fr.: lobe d'antenne   

A three-dimensional section of the → radiation pattern ofa directional antenna, bounded by one or more cones of nulls or by regions of diminished irradiance.

antenna; → lobe.

antenna pattern
  الگوی ِ آنتن   
olgu-ye ânten

Fr.: diagramme de rayonnement   

The response of an antenna to incident radiation as a function of the direction of incidence of the radiation. A generic antenna pattern consists of a → main lobe and a number of smaller → side lobes. Also called → radiation pattern.

antenna; → pattern.

antenna temperature
  دما‌ی ِ آنتن   
damâ-ye ânten

Fr.: température d'antenne   

In radio astronomy, a measure of the power absorbed by the antenna. In an ideal, loss-free radio telescope, the antenna temperature is equal to the brightness temperature if the intensity of the received radiation is constant within the main lobe. → antenna; → temperature.

antenna; → temperature.

Antennae galaxies
  کهکشان‌ها‌ی ِ شاخکی   
kahkešânhâ-ye šâxak

Fr.: galaxies des Antennes   

The pair of colliding galaxies NGC4038 and NGC4039 and the long arcing insect-like "antennae" of luminous matter revealed by optical telescopes. The "antennae" are believed to have been produced by the collision between the galaxies that began about 100 million years ago and is still occurring. The Antennae Galaxies, about 60 million → light-years from Earth, lie in the constellation → Corvus.

Antennae, plural of → antenna; → galaxy.

Kahkešânhâ, plural of kahkešângalaxy; šâxak "insect antenna," from šâx "horn" (Mid.Pers šâk, cf. Skt. sakha- "a branch, a limb," Arm. cax, Lit. šaka, O.S. soxa, PIE *kakhâ "branch") + -ak suffix denoting relation, affinity, similarity (as in dastak, pos(tak, pas(mak, xarak, nâxonak, mus(ak, eynak);

Aten asteroid
  سیارک ِ آتن   
sayyârak-e Aten

Fr.: astéroïde Aten   

A member of a class of → near-Earth asteroids with → perihelion distances between 0.983 and 1.0 → astronomical units. It is estimated that 6% of the total number of NEAs are Atens.

Aten; → asteroid.

attend
  آتانیدن   
âtânidan

Fr.: attendre   

1) To pay attention.
2) To be present at.

M.E. atenden, from O.Fr. atendre "to expect, wait for, pay attention," from L. attendere "give heed to," literally "to stretch toward," from → ad- "to" + tendere "stretch," → tension.

Âtânidan, from prefix â- + tân, from tan-, tanidan "to spin, twist, weave" (cf. tân "thread, warp of a web," variants târ "thread, warp, string," tâl "thread" (Borujerdi dialect), tur "fishing net, net, snare"); Mid.Pers. tanitan; Av. tan- to stretch, extend;" cf. Skt. tan- to stretch, extend;" tanoti "stretches," tantram "loom;" tántra- "warp; essence, main point;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch;" Lith. tiñklas "net, fishing net, snare;" PIE base *ten- "to stretch."

attendance
  ۱، ۲) آتانگری؛ ۲) آتانگران   
1, 2) âtângari; 2) âtângarân

Fr.: 1) service; 2) présence; 3) assistance   

1) The act or state of attending.
2) The act or state of going to or being present at a place or event.
3) The persons or number of persons present at a particular place or event.

attend; → -ance.

attendee
  آتانگر، پارگرتنده   
âtângar, pârgertandé

Fr.: participant   

A person who is present at a specific time or place.

From → attend + suffix -ee

Âtângar agent noun from → attend; pârgertandé agent noun from pârgertidan, → participate.

attention
  آتانش   
âtâneš

Fr.: attention   

1) The act or faculty of attending, especially by directing the mind to an object.
2) Observant care; consideration (Dictionary.com).

attend; → -tion.

attentive
  آتانمند   
âtânmand

Fr.: attentif   

1) Characterized by or giving attention; observant.
2) Thoughtful of others; considerate; polite; courteous (Dictionary.com).

attend; → -ive.

attenuate
  تنکیدن   
tonokidan (#)

Fr.: atténuer   

1) To reduce in force, value, amount, or degree. → attenuation, → attenuation factor.
2) To reduce the amplitude of an electrical signal with little or no distortion.

L. attenuatus, p.p. of attenuare "to make thin," from → ad- "to" + tenuare "make thin," from tenuis "thin;" cf. Gk. tanaos "thin, slender, elongated;" Skt. tanuka-, tanu- "thin;" Av. tan- "to stretch;" Pers. tonok "thin," as below; O.Ir. tanae "delicate, thin;" O.H.G. dunni "thin."

Tonokidan, from tonok "thin, slender, slight, tender, delicate" + -idan, infinitive suffix. Tonok, from Mid.Pers. tanuk, Av. root tan- "to stretch, extend," cognate with L. tenuis, as above.

attenuation
  تنکش   
tonokeš (#)

Fr.: atténuation   

The falling off of the energy density of radiation with distance from the source, or with passage through an absorbing or scattering medium.

Verbal noun of → attenuate.

attenuation coefficient
  همگر ِ تنکش   
hamgar-e tonokeš

Fr.: coefficient d'bsorption   

The fraction of a beam of → X-rays or → gamma rays that is absorbed or scattered per unit thickness of the → absorber. The linear attenuation coefficient, denoted by the symbol μ, appears in the equation I(x) = I0ex, where I(x) is the intensity at depth of x cm and I0 is the original intensity.

attenuation; → coefficient.

attenuation factor
  کروند ِ تنکش   
karvand-e tonokeš

Fr.: facteur d'atténuation   

The ratio of the radiation intensity after traversing a layer of matter to its intensity before.

attenuation; → factor.

brightening
  روشنش   
rowšaneš

Fr.: embrillancement   

The act or process of becoming bright or brighter. → limb brightening, → gravity brightening

Verbal noun of brighten, from → bright.

calculus of tensors
  افماریک ِ تانسورها   
afmârik-e tânsorhâ

Fr.: calcul tensoriel   

The branch of mathematics dealing with the differentiation of tensors.

calculus; → tensor.

Afmârik, → calculus; → tensor.

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