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: 373
objective prism
  منشور ِ بر‌آختی   
manšur-e barâxti

Fr.: prisme-objectif   

A dispersing prism placed in front of a telescope objective to produce spectra of all luminous objects in the field of view.

objective; → prism.

objective probability
  شوانایی ِ بر‌آختی   
šavânâi-ye barâxti

Fr.: probabilité objective   

A probability determined by the long-term frequency of an event; in contrast to subjective probability.

objective; → probability.

objectivity
  بر‌آختیگی   
barâxtigi

Fr.: objectivité   

1) The state or quality of being → objective. Opposite of → subjectivity.
2) Ability to view things objectively.
3) External reality.

objective + → -ity.

oblate
  پخ   
pax (#)

Fr.: aplati   

Adjective meaning flattened, as → oblate spheroid. Opposed to → prolate.

From L. ob- "toward" + latus, abstracted from its opposite, prolatus "lengthened."

Pax "oblate," of unknown etymology.

oblate spheroid
  کره‌وار ِ پخ   
korevâr-e pax

Fr.: sphéroïde aplati   

An ellipsoid produced by rotating an ellipse through 360° about its minor axis. Compare with → prolate spheroid.

oblate; → spheroid.

oblateness
  پخی   
paxi (#)

Fr.: aplatissement   

The property possessed by a round body that is flattened at the poles.

Noun from → oblate.

obligate
  ۱) فریزیدن؛ ۲) فریزیده   
1) farizidan; 2) farizidé

Fr.: obliger   

1a) To bind or oblige morally or legally.
1b) To pledge, commit, or bind (funds, property, etc.) to meet an obligation.
2a) Morally or legally bound; obliged; constrained.
2b) Necessary; essential (Dictionary.com).

Back-formation from → obligation.

obligation
  فریز   
fariz (#)

Fr.: obligation   

1) Something by which a person is bound or obliged to do certain things, and which arises out of a sense of duty or results from custom, law, etc.
2) Something that is done or is to be done for such reasons (Dictionary.com).

M.E. obligacioun, from O.Fr. obligacion "obligation, duty, responsibility," from L. obligationem "an engaging or pledging," literally "a binding," noun of action from p.p. stem of obligare "to bind, bind up, bandage," from → ob- "to" + ligare "to bind," from PIE root *leig- "to bind."

Fariz, from Mid.Pers. frêz "obligation; duty."

obligatory
  فریزگون   
farizgun

Fr.: obligatoire   

Required as a matter of obligation; mandatory; incumbent; compulsory.

M.E., from L.L. obligatorius "binding," → obligate, + -tory, from L. -torius, from → -tor + -ius.

Farizgun, from fariz, → duty, + -gun "manner, fashion."

oblique
  یکور   
yekvar (#)

Fr.: oblique   

Neither perpendicular nor horizontal; having the axis not perpendicular to the base; slanting; sloping.

From M.Fr. oblique, from L. obliquus "slanting, sidelong, indirect," from ob "against" + root of licinus "(of an ox whose corn tips are) bent upward," from PIE base *lei- "to bend, be movable."

Yekvar, literally "slantingn to a side," from yek-, → one, + var "side," variant bar "side; breadth; breast" (Mid.Pers. var "breast;" Av. vouru "wide, broad, extended" (vourucašāni- "looking far"), related to varah- "breast;" cf. Skt. urú- "wide, broad," úras- "breast;" Gk. eurus "wide, broad;" PIE base uer-, ueru-s"wide, broad").

oblique rotator model
  مدل ِ چرخنده ِ یکور   
model-e carxande-ye yekvar

Fr.: modèle de rotateur oblique   

A stellar model in which the rotation axis is tilted relative to the magnetic dipole axis. As the star rotates, observable quantities (e.g. the line-of-sight component of the magnetic field, stellar brightness, emission lines) are modulated according to the rotational period. Such a model was first put forward by D. Stibbs (1950, MNRAS, 110, 395).

oblique; → rotator; → model.

oblique sphere
  سپهر ِ یکور   
sepehr-e yekvar

Fr.: sphère oblique   

The celestial sphere when the circles parallel to the equator are cut obliquely by the horizon plane, which divides them into two unequal parts. In other words, the sphere when its axis is oblique to the horizon of the place.

oblique; → sphere.

obliquity
  یکوری   
yekvari

Fr.: obliquité   

1) General: The quality or state of being oblique.
2) The → angle that an object's → rotational axis makes with its → orbital axis. In other words, the angle between its → equatorial plane and → orbital plane. Same as → axial tilt.

State noun of → oblique.

obliquity of the ecliptic
  یکوری ِ هورپه   
yekvari-ye hurpeh

Fr.: obliquité de l'écliptique   

The angle between the Earth's → equatorial plane and the → ecliptic. Its present value is 23°26'13.5'' (or 23.43708 degrees). The effects of → precession and → nutation cause it to change between extreme values of 22.1 and 24.5 degrees over a period of approximately 41,000 years. It is currently decreasing.

obliquity; → ecliptic.

oblong
  درازک   
derâzak

Fr.: oblong   

Elongated, usually from the square or circular form.

Late M.E. oblonge, from L. oblongus "rather long," from ob- a prefix meaning "toward, to, on, over, against" + longus, → long.

Derâzak, from derâz "long," → length + -ak suffix.

OBN star
  ستاره‌ی ِ OBN   
setâre-ye OBN

Fr.: étoile OBN   

A → nitrogen (N)-rich → O-type or → B-type star.

O star; → B star; → nitrogen; → star.

obscuration
  تیره‌کرد، تیره‌شد   
tirekard, tirešod

Fr.: obscurcissement   

1) The act of obscuring.
2) The state of being obscured.

obscure; → -tion.

obscure
  ۱) تیره؛ ۲) تیره‌کردن   
1) tiré (#); 2) tiré kardan (#)

Fr.: 1) obscur; 2) obscurcir   

1a) Lacking in light or illumination; dark; dim; murky.
1b) Indistinct to the sight or any other sense.
1c) Not clear to the understanding.
2) To make dark, dim, indistinct, etc.

From O.Fr. obscur "dark, dim, not clear," from L. obscurus "covered over, dark, obscure," from ob "over" + -scurus "covered," from PIE *(s)keu- "to cover, conceal;" from which derives also the term → sky.

Tiré, from Mid.Pers. târag "dark, turbid," related to târik "dark," Mid.Pers. târig "dark," târ "darkness," Av. taθra- "darkness," taθrya- "dark," cf. Skt. támisrâ- "darkness, dark night," L. tenebrae "darkness," Hittite taš(u)uant- "blind," O.H.G. demar "twilight."
Tiré kardan compound verb with kardan "to do," → -ize.

obscuring torus
  چنبر ِ تیره‌ساز   
canbar-e tiresâz

Fr.: tore obscurcissant   

A structure of dust and gas postulated to surround the central → black hole in an → active galactic nucleus (AGN). The presence of an obscuring torus allows the unification of the two main types of AGNs containing a → broad-line region (Type I) and a → narrow-line region (Type II), respectively. In this unified model, the two types represent the same sort of object, the appearance of which depends on the viewer's → line of sight. The best evidence for this model comes from spectropolarimetry observations of some type II AGNs in which broad → emission lines are seen in → polarized light, as would happen if the broad-line region truly were hidden, and the light were being reflected off the torus and into the viewer's line of sight.

obscure; → torus.

obscurity
  تیرگی   
tiregi (#)

Fr.: obscurité   

The state or quality of being obscure.

obscure + → -ity.

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