An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -oi obj obs obs oct off old one ope opp opt opt orb ord ori ort osc out ove ozo > >>

Number of Results: 383
optical double star
  ستاره‌یِ دوتایی ِ دیدگانی   
setâre-ye dotâyi-ye didgâni

Fr.: étoile double optique   

A pair of stars that lie close to each other in the sky by chance, but are not physically associated, in contrast to a true → binary star.

optical; → double star.

optical fiber
  فیبرِ نوری   
fibr-e nuri

Fr.: fibre optique   

A thin filament of drawn or extruded glass or plastic having a central core and a cladding of lower index material to promote internal reflection. It may be used singly to transmit pulsed optical signals (communications fiber) or in bundles to transmit light or images.

optical; → fiber.

optical illusion
  سفمانِ دیدگانی   
safmân-e didgâni

Fr.: illusion d'optique   

A perception of visual stimuli in which what is perceived is in a way different from the way it is in reality. Same as visual illusion.

optical; → illusion.

optical instrument
  سازالِ نوری   
sâzâl-e nuri

Fr.: instrument optique   

An instrument that either processes light waves to enhance an image or analyzes light waves to determine one of a number of characteristic properties.

optical; → instrument.

optical jet
  شان ِ نوری   
šân-e nuri

Fr.: jet optique   

An → astrophysical jet which is visible in the optical range of the electromagnetic radiation.

optical; → jet.

optical oblateness
  پخی ِ نوری   
paxi-ye nuri

Fr.: aplatissement optique   

(polar flattening) The ratio of the difference between equatorial and polar diameters to the equatorial diameter. A sphere has an oblateness of 0; an infinitely thin disk has an oblateness of 1 (Ellis et al., 2007, Planetary Ring Systems, Springer).

optical; → oblateness.

optical path
  راهِ نوری   
râh-e nuri (#)

Fr.: chemin optique   

In → geometric optics, the distance a light ray would travel in a vacuum in the same time it travels from one point to another, a specified distance, through one or more optical media.

optical; → path.

optical pulsar
  پولسارِ نوری، تپار ِ ~   
pulsâr-e nuri, tapâr-e ~

Fr.: pulsar optique   

A member of a rare class of pulsars, such as the → Crab pulsar and → Vela pulsar, which can be detected in the visible spectrum.

optical; → pulsar.

optical pumping
  پمپشِ نوری   
pompeš-e nuri

Fr.: pompage optique   

A process in which light energy is used to raise electrons from a lower energy level in an atom or molecule to a higher one. It is commonly used in laser construction, to pump the active laser medium so as to achieve population inversion. The technique was developed by 1966 Nobel Prize winner Alfred Kastler in the early 1950's.

optical; → pumping.

optical system
  راژمان ِ نوری، ~ نوریک   
râžmân-e nuri, ~ nurik

Fr.: système optique   

A collection of lens, prisms, mirrors, and/or other devices, placed in some specified configuration, to act on light (reflect, refract, disperse, polarize, etc.) and perform some definite optical function.

optical; → system.

optical thickness
  ستبرایِ نوری   
setabrâ-ye nuri

Fr.: épaisseur optique   

Same as → optical depth.

optical; → thickness.

optical transfer function (OTF)
  کریا‌یِ تراوژ ِ نوری   
karyâ-ye tarâvaž-e nuri

Fr.: fonction de transfert optique   

The function that provides a full description of the imaging quality of an optical system. A combination of the → modulation transfer function (MTF) and the → phase transfer function (PTF) , the OTF describes the spatial (angular) variation as a function of spatial (angular) frequency.

optical; → transfer; → function.

optical window
  روزنه‌یِ نوری   
rowzane-ye nuri

Fr.: fenêtre optique   

The optical portion of the electromagnetic spectrum that passes through the atmosphere all the way to the ground.

optical; → window.

  نورانه، نوریکانه   
nurâné, nurikâné

Fr.: optiquement   

Adverb of → optical.

optical + -ly.

Nurâné, from nur, → light, + -âné "-ly;" nurikâné, from nurik, → optical, + -âné "-ly."

optically active
  نورانه ژیرا   
nurâné žirâ

Fr.: optiquement actif   

Relating to → optical activity.

optically; → active.

optically thick
  نورانه ستبر، نوریکانه ~   
nurâné setabr, nurikâné ~

Fr.: optiquement épais   

The qualifier of a medium in which the → optical depth is large, significantly larger than 1.

optically; → thick.

optically thick wind
  باد ِ نورانه ستبر   
bâd-e nurâné setabr

Fr.: vent optiquement épais   

A wind with the → sonic point located at large optical depth for continuum. In particular, → Wolf-Rayet star winds are → optically thick. However, the outer parts of W-R winds are → optically thin for continuum, and in those regions the matter flow is driven by the same mechanism as in the winds of OB stars.

optically; → thick; → wind.

optically thin
  نورانه تنک، نوریکانه ~   
nurâné tonok, nurikâné ~

Fr.: optiquement mince   

The qualifier of a medium in which the → optical depth is large, significantly smaller than 1.

optically; → thin.

optically violent variable (OVV) quasar
  کو‌آسارِ ورتنده‌ی ِ نورانه سورا   
kuâsâr-e vartande-ye nurâné surâ

Fr.: quasar variable optiquement violent   

A member of a small subset of quasars consisting of bright radio galaxies whose flux of visible light output can vary by as much as 50% in a single day.

optically; → violent; → variable; → quasar.

  ۱)عینک‌ساز؛ ۲) نوریکار، نوریک‌کار   
1) eynak-sâz; 2) nurikâr, nurik-kâr

Fr.: opticien   

1) A maker or seller of optical glass.
2) A person specialized in optical instruments.

From Fr. opticien, from M.L. optic(a), → optics, + -ien "-ian."

1) Eynak-sâz "eyeglass maker," from eynakeyeglasses + sâz agent noun of sâxtan, sâzidan "to build, make, fashion; to adapt, adjust, be fit" (from Mid.Pers. sâxtan, sâz-, Manichean Parthian s'c'dn "to prepare, to form;" Av. sak- "to understand, to mark," sâcaya- (causative) "to teach").
2) Nurikâr, nurik-kâr "optics performer, optics workman, optics specialist," from nurik, → optics, + -kâr variants -gar,-gâr, from kar-, kardan "to do, to make" (Mid.Pers. kardan, O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "makes," cf. Skt. kr- "to do, to make," krnoti "makes," karma "act, deed;" PIE base kwer- "to do, to make").

<< < -oi obj obs obs oct off old one ope opp opt opt orb ord ori ort osc out ove ozo > >>