An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -fy fac fal fas fee Fer fib fil fin fir Fla flo flu Fok for for Fou fra fre Fre ful fuz > >>

Number of Results: 428
filamentary nebula
  میغ ِ رشته‌ای   
miq-e rešteyi

Fr.: nébuleuse filamentaire   

A nebula, generally ionized, consisting of filament-like structures of gas, such as the Veil Nebula (NGC 6960) or the supernova remnant IC 443.

Filamentary adj. of → filament; → nebula.

filar micrometer
  ریزسنج ِ زهی   
riz-sanj-e zehi

Fr.: micromètre filaire   

An instrument used with a telescope for accurately measuring small angular separations between two celestial bodies (as between binary stars). The instrument consists of two parallel fine wires with one wire being fixed and the other movable by means of a finely threaded screw.

Filar, from L. fil(um) "a thread" (see the paragraph below) + -ar variant of the adjective-forming suffix → -al; → micrometer.

Kehsanj, → micrometer; zehi adj. of zeh "string, bow-string;" Mid.Pers. zih "bow-string," zig "string; astronomical table" (loaned into Ar. as zij); Av. jiiā- "bow-string;" cf. Skt. jiyā- "bow-string;" Gk. bios "bow;" L. filum "thread;" Arm. jil "string, line;" Lith. gijà "thread;" Russ. žica "thread;" PIE base *gwhi- "thread, tendon."

parvandé (#)

Fr.: fichier   

In computer science, a collection of related data or program records stored on a support.

From M.E. filen, from M.F. filer "to string documents on a thread," O.F. filer "to wind or spin thread," from L.L. filare "to spin, draw out in a long line," from L. filum "thread," from PIE base *gwhi- "thread, tendon;" cf. Gk. bios "bow;" Skt. jiyā- "bow-string;" Av. jiiā- "bow-string;" Mod.Pers. zeh "bow-string;" Arm. jil "string, line," Lith. gijà "thread;" Russ. žica "thread."

Parvandé "file," initially "a bundle, roll, truss (of clothes)," from Mid.Pers. parwastan, parwand- "to surround, enclose, contain, comprise," from par-, variants far-, par-, pirâ- "around, about" (Mid.Pers. pêrâ; O.Pers. pariy "around, about," Av. pairi "around, over;" Skt. pari; Indo-Iranian *pari- "around;" PIE base *per- "through, across, beyond;" cf. Gk. peri "around, about, beyond;" L. per "through") + vand-/band- stem of vastan/bastan "to bind, shut;" O.Pers./Av. band- "to bind, fetter," banda- "band, tie" (cf. Skt. bandh- "to bind, tie, fasten;" PIE *bhendh- "to bind;" Ger. binden; E. bind).

filling factor
  کروند ِ پُری   
karvand-e pori

Fr.: facteur de remplissage   

Of a molecular cloud or a nebula, the ratio of the volumes filled with matter to the total volume of the cloud.

Filling, from fill, from O.E. fyllan, from P.Gmc. *fullijan (cf. Du. vullen, Ger. füllen "to fill"), a derivative of adj. *fullazfull; → factor.

Karvand, → factor; pori, from por, → full.

pâlâyé (#)

Fr.: filtre   

1) General: A device for separating the constituents of a system according to a physical property. In particular, a device for removing solid matter suspended in a liquid by forcing the suspension through a material which retains the solid matter while allowing the liquid to pass.
2) Optics: A device for transmitting electromagnetic radiation with restricted ranges of wavelength. Two types are generally used, → glass filters and → interference filters. See also → neutral density filter.
3) Electronics: A circuit or equipment allowing the transmission of desired frequencies and the elimination of others.

From M.L. filtrum "felt," which was used to strain impurities from liquid, from W.Gmc. *filtiz.

Pâlâyé, from pâlây present stem of pâludan "to filter, purify;" Mid.Pers. pâludan, pâlây- "to strain, filter, purify," from Proto-Iranian *pari-harz-, from prefix *pari- "around," → peri-, + harz- "to let go, release;" cf. Av. pairi.harəz- "to filter," from pairi- "around, over" (cf. Skt. pari; Gk. peri "around, about, beyond;" L. per "through;" PIE base *per- "through, across, beyond") + harəz- "to release" (especially water, liquid; cf. Chorasmian pžy- "to purify, filter;" Arm. (loanword) parzel "to filter, purify;"

pâyâni (#)

Fr.: final   

Pertaining to or coming at the end; last in place, order, or time.

M.E., from O.Fr. final from L. finalis "of or pertaining to an end, concluding," from finis "end."

Pâyâni from pâyân "end, extremity; limit, boundary," from pâ(y) "foot; step; track," → foot.

yâft (#)

Fr.: trouvaille   

A meteorite that was not seen to fall, but was found at some later date, as opposed to a → fall.

O.E. findan "to come upon," from P.Gmc. *finthanan (cf. M.Du. vinden, Ger. finden), from PIE *pent- "to go, pass, path, bridge;" cf. Av. paθ-, variants paθi-, paθā-, pantay-; Mid/Mod.Pers. pand "path, advice, councel;" Khotanese pande "road, path;" Ossetic fœndœg "path, road;" cf. Skt. pánthā- "road, path, course;" Gk. patos "path, way," pontos "sea;" L. pons "bridge, path."

Yâft, past stem of yâftan, yâbidan "to find, discover; to obtain, acquire;" Mid.Pers. ayâftan, ayâpênitan "to reach, attain;" Manichean Mid.Pers. 'y'b "to attain;" Parthian, Sogdian (+ *pati-) pty'b "to reach, obtain;" Av. ap- "to reach, overtake," apayeiti "achieved, reached;" Skt. âp- "to reach, gain," âpnoti "reaches, gains;" Gk. hapto, haptomai "to touch, cling to, adhere to;" L. apiscor "touch, reach;" PIE base *ap- "to take, reach."

yâbandé (#)

Fr.: chercheur   

A low-power telescope with a wide field of view attached to a larger telescope with the optical axes of both telescopes parallel. The finder is used to help point the larger telescope to the desired viewing location.

Agent noun of → find.

finding chart
  نگاره‌ی ِ یابش   
negâre-ye yâbeš

Fr.: carte de champ   

A sketch or image used to recognize objects in the field of view of a telescope.

Finding, noun of → find; chart, from M.Fr. charte "card, map," from L. charta "leaf of paper, tablet," from Gk. khartes "layer of papyrus."

Negâre-ye yâbeš, from negâré, from negâr "picture, figure" (verb negârdan, negâštan "to paint"), from prefix ne- "down; into," → ni-, + gâr, from kar-, kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base kwer- "to do, to make"); yâbeš, verbal noun of yâftan, → find.

nâzok (#)

Fr.: fine   

Very thin or slender. → fine structure, → fine-structure constant.

M.E. fin, from O.Fr. fin "perfected, of highest quality," from L. finis "end, limit."

Nâzok "thin, slender, subtle," from Mid.Pers. nâzuk "tender, gentle," variant nâzik, from nâz "joy, pride, glory" + → -ik.

fine dust
  ریزگرد، غبار ِ نازک   
rizgard, qobâr-e nâzok

Fr.: poussière fine   

Meteorology: An → inhomogeneous  → mixture of tiny, part → solid, part → liquid or → gaseous  → particles that are, in average, smaller than ten → microns. The constituents are soot, heavy metals, organic substances, and dioxins. The smaller these dust particles, the deeper they penetrate into the lung. Larger particles are intercepted by mucous membrane in nose, mouth, and throat but smaller particles can penetrate the smallest lung bronchioles and may cause severe damage (various respiratory disorders, lung cancer) → particulate matter.

fine; → dust.

fine structure
  ساختار ِ نازک   
sâxtâr-e nâzok

Fr.: structure fine   

Closely spaced components seen at high resolution in a → spectral line. The phenomenon is explained by the fact that instead of a single → energy level corresponding to a given value of the → quantum number  n, there are actually a number of energy levels lying close to one another. → fine-structure constant, → fine-structure line.

fine; → structure.

fine-structure constant
  پایای ِ ساختار ِ نازک   
pâyâ-ye sâxtâr-e nâzok

Fr.: constante de la structure fine   

A measure of the strength of → interaction between a → charged particle and the → electromagnetic field. It is a → dimensionless number expressed (in → cgs units) by α = e2c, where e is the → electron charge, ħ is the → reduced Planck's constant, and c is the → speed of light. It is approximately equal to 1/137 or 7.3 x 10-3. The smallness of this number is of great importance since it determines the size of → atoms and the → stability of → matter.

fine structure; → constant.

fine-structure line
  خط با ساختار ِ نازک   
xatt bâ sâxtâr-e nâzok

Fr.: raie de structure fine   

A → spectral line whose → energy levels have a → fine structure. Examples are [C II] 157.7 μm (→ singly ionized carbon), [O III] 88 μm, and [Ne II] 12.8 μm.

fine; → structure; → line.

angošt (#)

Fr.: doigt   

Any of the terminal members of the hand, especially one other than the thumb (

M.E., from O.E. fingor, cognate with Ger. Finger, Du. vinger, O.N. fingr, Goth. figgrs.

Angošt, variants angol, angul (also angal "loop"); Mid.Pers. angust; Av. angušta- "toe," ank- "curved, crooked;" cf. Skt. angustha- "thumb," angula- "finger," ankah "hook, bent;" Gk. angkon "elbow," angkura "anchor;" L. angulum "corner;" Lith. anka "loop;" O.E. ancleo "ankle;" O.H.G. ango "hook;" PIE *ang-/*ank- "to bend".

fingering convection
  همبز ِ انگشتوار   
hambaz-e angoštvâr


A weak yet important kind of mixing that results from → fingering instability in stars within → radiative zones that have an unstable mean → molecular weight  → gradient. Also called → thermohaline convection.

finger; → -ing; → convection.

fingering instability
  ناپایداری ِ انگشتوار   
nâpâydâri-ye angoštvâr

Fr.: instabilité à traines   

A type of instability that often occurs in fluids which are thermally stably stratified, but have an inhomogeneous composition. A well-known example, found in upper layers of the Earth's oceans, is → salt fingers. Similar fingering instabilities can occur in any other thermally stably stratified solution, provided the concentration of the slower-diffusing solute increases with height. The saturated state of this instability, → fingering convection, takes the form of tightly-packed, vertically-elongated plumes of sinking dense fluid and rising light fluid, and significantly enhances the vertical transport of both heat and chemical composition. The fingering instability occurs in stars within radiation zones that have an unstable mean → molecular weight  → gradient (μ gradient). This situation is often found as a result of material accretion onto a star by anything from a single or multiple planets, to material from a dust-enriched or debris accretion disk, or material from a more evolved companion. It also naturally arises in the vicinity of the → hydrogen shell burning in → red giant branch (RGB) stars, and in thin element-rich layers near the surface of intermediate-mass stars. The fingering instability initially takes the form of thin tubes, hence the name "finger," within which the fluid moves vertically. The tubes rapidly break down, however, as a result of parasitic shear instabilities that develop inbetween them, and the fingering instability eventually saturates into a state of homogeneous fingering convection where the typical aspect ratio of the eddies is closer to one (P. Garaud et al., 2015, arXiv:1505.07759).

finger; → -ing; → instability.

fingers of God
  انگشتان ِ خدا   
angoštân-e Xodâ

Fr.: doigts de Dieu   

A → redshift space distortion which causes the dense central regions of → galaxy clusters to appear elongated along the → line of sight. This effect is attributed to random velocities in clusters of galaxies deviating from pure → Hubble flow. For an observer galaxies with peculiar velocity perpendicular to the line of sight do not change the redshift, which is given just by the normal Hubble expansion. On the contrary, galaxies with peculiar velocity along the line of sight appear with a different redshift, resulting from the Hubble expansion velocity plus the peculiar velocity. Since this affects only redshift and not position on the sky, the stretching occurs only radially, toward the observer. See also → Kaiser effect, → peculiar velocity.

finger; → God.

karânmand (#)

Fr.: fini   

1) Math: The opposite of → infinite.
2) Physics: Either non-infinite or non-zero.

From L. finitus, p.p. of finire "to limit, set bounds, end."

Karânmand, from karân "boundary, side, end, coast" + -mand adjective suffix. Karân, variants karâné, kenâr, from Mid.Pers. karân, karânak, kenâr "edge, limit, boundary," Av. karana- "side, boundary, end."

finite population
  پرینش ِ کرانمند   
porineš-e karânmand

Fr.: population finie   

A → statistical population consisting of individuals or items which are finite in number.

finite; → population.

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