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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu coa coe coh col col col com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos Cou cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis div dog Dop dou dra dua dus dwa dyn e-m ear ecl eco eff ein Ein elb ele ele ele ele Els emi emp ene enr env epi equ equ Eri est Euc eva evo exc exc exh exo exp exp ext ext f-n Fah fam fau fee Fer fib fil fin fir fix fle flu foc for for for fra fre fre fri fun fuz gal gal gal Gan gau GCN gen geo geo geo geo Gl glo gra gra gra gra gra gre gro GW1 hab hal han HAR haz hea hel hel Hen Her heu Hig Hil hol hop hor hou Hub Hum Hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind ine inf inf inf inh INP ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos Jun K2 Kep key kin Kol lag lam Lan lar las lav lea leg len lev lig lim lin lin lin lis lob loc log lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal mar mas mas mat max mea mea mee Men mer met met met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxy pal pan par Par par par pas pea Pen per per per per per pet pha pho pho pho phy pie Pit Pla pla pla pla ple Poi pol pol pol pol pop pos pos pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sah san Sat sca Sch Sch scr sec sec sec sei sel sem sep set sha she sho sid sig sil sim sin sit sky slu sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spl spr sta sta sta sta sta ste ste sti sto str str sub sub sub sug sun sup sup sup sup sur syl syn sys tal Tay tel ten ter tex the the the thi tho thu tid tim tod top tot tra tra tra tra tri tri tro tru tur twi Typ UFO ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yel you zer zod > >>

Number of Results: 12948 Search : far
dawn
  پگاه، سپیده دم، بامداد   
pegâh (#), sepidedam (#), bâmdâd (#)

Fr.: aube, point du jour, aurore   

The first daylight in the sky before sunrise, equivalent to morning astronomical → twilight; opposed to → dusk.

M.E. dawen (v.), from O.E. dagung, from dagian "to become day," from root of dægday.

Pegâh, from Mid.Pers. pa gâh, from pa "to; for; in; on; with; by; according to," O.Pers. upā, Av. upa "toward, with, on, in, in the time of" (cf. Skt. úpa "toward, together with, under, near to, on," Gk. hypo "under, below," L. sub "under," Ger. auf, E. up; PIE *upo "under, up from under, over") + gâh "time," O.Pers. gāθu-, Av. gātav-, gātu- "place, throne, spot" (Skt. gátu- "going, motion; free space for moving; place of abode," PIE *gwem- "to go, come").
Sepidedam, from sepidé "whitish; dawn," from sepid "white" (Mid.Pers. spêt, Av. spita- "white," Skt. śveta- "white," Lith. sviesti "to shine," svaityti "to brighten," P.Gmc. *khwitaz, O.E. hwit, E. white, Ger. weiss, PIE *kwintos/*kwindos "bright") + dam "moment, time; to blow, breathe; smoke" (Mod./Mid.Pers. damidan "to blow, breathe," Av. dāδmainya- "blowing up," Skt. dahm- "to blow," dhámati "blows," Gk. themeros "austere, dark-looking," Lith. dumti "to blow," PIE dhem-/dhemə- "to smoke, to blow").
Bâmdâd, from Mid.Pers. bâmdât, Av. bāmya- "the dawn," from bā- "to shine" (cf. Skt. bhā- "light, brightness," Gk. phainomai "to appear, shine, gleam," Arm. banam "to open, uncover," PIE *bhā- "to shine").

Dawn spacecraft
  فضاناو ِ داؤن   
fazânâv-e Dawn

Fr.:   

NASA's mission to explore the two largest objects in the → asteroid belt, the asteroid Vesta and the → dawarf planet Ceres, gathering data relating to their composition, internal structure, density and shape. Launched in September 2007, Dawn entered the orbit of → Vesta in July 2011 and spent 16 months there before leaving for → Ceres. It entered Ceres orbit on March 6, 2015. The Dawn spacecraft is made of aluminium and graphite composite, it has a dry mass of 747.1 kg and a mass of 1217.7 kg when fully fuelled prior to launch. The spacecraft is a box-shaped design measuring 1.64m × 1.27m × 1.77m.

dawn; → spacecraft.

day
  روز   
ruz (#)

Fr.: jour   

The length of time it takes Earth (or a planet) to rotate once on its axis relative to some external reference. The day is measured in several ways, depending on this reference, → sidereal day; → solar day; → mean solar day.

M.E., from O.E. dæg (cf. Ger. Tag, Swedish and Danish dag "day"), from PIE base *dhegh- "to burn." Not related to L. dies "day" (from *dyeu- "to shine," → diurnal), but rather to Av. dag- "to burn," dažaiti "burns," Mod.Pers. dâq "hot," Skt. dah- "to burn," dáhati, Gk. tephra "ash," L. fovere "to boil," Albanian djeg "to burn," Russ. žeč' "to burn," Lith. dagas "hot season," degti "to burn," O.Prus. dagis "summer."

Ruz "day," from Mid.Pers. rôc, O.Pers. raucah-, Av. raocah- "light, luminous; daylight," Skt. roka- "brightness, light," cognate with Gk. leukos "white, clear," L. lux "light" (also lumen, luna), PIE base *leuk- "light, brightness". The Persian words rowšan "bright, clear," foruq "light," and afruxtan "to light, kindle" also belong to this family, as well as the E. light, Ger. Licht, and Fr. lumière.

daylight meteor
  شهاب ِ روز   
šahâb-e ruz

Fr.: météore de jour   

A → meteor detected using → radar techniques during daylight or when skies are cloudy.

day; → light; → meteor.

daylight saving time
  وخت ِ نور‌اندوزی، وقت ِ ~   
vaxt-e nur anduzi, vaqt-e ~

Fr.: heure d'été   

A system of adjusting the official local time in some countries in order to provide a better match between the hours of daylight and the active hours of work and school. The "saved" daylight is spent on evening activities which get more daylight, rather than being "wasted" while people sleep past dawn. Although known also as summer time, it includes the spring season and nearly half of autumn.

day; → light; saving, from save, from O.Fr. sauver, from L.L. salvare "to secure," from L. salvus "safe," PIE *solwos, from base *sol- "whole" (cf. O.Pers. haruva-, Av. haurva- "whole, intact," Mod.Pers. har "every, all; any," Skt. sarva- "whole, entire," Gk. holos "whole"); → time.

Vaxt, written vaqtوقت but pronounced vaxtوخت, is a Pers. word meaning "portion (of time)". Its variants and related words in Mod./Mid.Pers. are: baxt "what is alloted, fate, fortune," baxš "portion, part, division," baxšidan, baxtan "to divide, distribute, grant," Av. base bag- "to attribute, allot, distribute," baxš- "to apportion, divide, give to," baxta- "what is alloted (luck, fortune)," baxədra- "part, portion," baγa- "master, god," O.Pers. bāji- "tribute, tax," cf. Skt. bhaj- "to share, divide, distribute, apportion," bhájati "divides," bhakta- "alloted; occupied with; a share; food or a meal, time of eating?," Gk. phagein "to eat (to have a share of food)"; PIE base *bhag- "to share out, apportion."
nurlight.
anduzi, verbal noun of anduxtan "to save; acquire, gather," from Mid.Pers. handôxtan, handôz- "to gain, acquire, amass," from *ham-tuj-, from ham- "together," → com- + *tuj- "to save, gather, (re)pay," cf. Skt. tuj- "to promote, be strong, move quickly."

daytime
  روز‌هنگام   
ruzhangâm (#)

Fr.: temps de jour   

The time interval when the Sun is above the horizon for a given position.

day; → time.

Ruzhangâm, from ruzday + hangâm "time, hour, season," Mid.Pers. hangâm "time, epoch, season," Av. ham-gam- "to meet together," from ham- "together," → com- + gam- "to come; to go," jamaiti "goes," O.Pers. gam- "to come; to go," Mod.Pers. âmadan "to come," Skt. gamati "goes," Gk. bainein "to go, walk, step," L. venire "to come," Tocharian A käm- "to come," O.H.G. queman "to come," E. come; PIE root *gwem- "to go, come."

DB white dwarf
  سفید‌کوتوله‌ی ِ DB   
sefid kutule-ye DB

Fr.: naine blanche DB   

A → white dwarf whose spectrum shows strong He I in the absence of hydrogen or metal lines.

D short for → dwarf; B a convention; → white.

DC white dwarf
  سفید‌کوتوله‌ی ِ DC   
sefid kutule-ye DC

Fr.: naine blanche DC   

A → white dwarf showing a continuous spectrum with no readily apparent lines.

D short for → dwarf; C a convention; → white.

de Broglie equation
  هموگش ِ دوبروی   
hamugeš-e de Broglie

Fr.: équation de de Broglie   

According to the → de Broglie hypothesis, which has been verified by experiments, every → particle of matter, whatever its nature, has a characteristic → wavelength associated with its wavelike quantum aspect. The de Broglie equation gives the equivalent wavelength of a moving particle: λ = h/mv, where h is → Planck's constant, m the mass of the particle, and v its velocity.
See also: → de Broglie wavelength, → Davisson-Germer experiment.

Named after Louis Victor de Broglie (1892-1987), French physicist, creator of a new field in physics, wave mechanics, who won the Nobel prize in physics in 1929. → equation

de Broglie hypothesis
  انگاره‌ی ِ دوبروی   
engâre-ye de Broglie

Fr.: hypothèse de de Broglie   

The suggestion by Louis de Broglie in 1924 whereby if → electromagnetic waves possess particle properties (→ particle nature), then it might be reasonable to suppose that material particles, such as → electrons, should possess wave properties (→ wave nature). The de Broglie hypothesis was based on the intuitive feeling that nature seems to have strong attachment to symmetry. In other words, if radiation has particle-like properties, then material particles should possess wave-like properties. At the time no direct experimental evidence was present for the validity of this suggestion. The first confirmation of de Broglie's hypothesis was provided by the → Davisson-Germer experiment. See also → wave-particle duality;

de Broglie equation; → hypothesis.

de Broglie wavelength
  موج-طول ِ دوبروی   
mowjtul-e de Broglie

Fr.: longueur d'onde de Broglie   

The wavelength of the wave associated with a → particle as given by the → de Broglie equation.

de Broglie equation; → wavelength.

de Sitter Universe
  گیتی ِ دوسیتر   
giti-ye de Sitter

Fr.: Univers de de Sitter   

A solution to → Einstein's field equations of → general relativity which contains no ordinary matter (ΩM = 0) or radiation (ΩR = 0), is → Euclidean (k = 0), but has a → cosmological constantΛ > 0). The Universe expands exponentially forever. This solution was the first model expanding of → expanding Universe. See also → empty Universe, → Milne Universe.

After the Dutch mathematician and physicist Willem de Sitter (1872-1934) who worked out the model in 1917; → universe.

de Vaucouleurs law
  قانون ِ دووکولور   
qânun-e de Vaucouleurs

Fr.: loi de Vaucouleurs   

A mathematical expression describing the → surface brightness profile of a typical → elliptical galaxy, whereby the projected luminosity distribution varies as exp(-R)1/4.

de Vaucouleurs radius; → law.

de Vaucouleurs radius
  شعاع ِ دووکولور   
šo'â'-e de Vaucouleurs

Fr.: rayon de Vaucouleurs   

An → isophotal radius of a galaxy, where the → surface brightness in the B band falls to 25 mag arcsec-2.

After the French-born American astronomer Gérard de Vaucouleurs (1918-1995); → radius.

de Vaucouleurs system
  راژمان ِ دووکولور   
râžmân-e de Vaucouleurs

Fr.: système de Vaucouleurs   

A widely used scheme for classifying galaxies which is an extension to the → Hubble sequence Hubble sequence. De Vaucouleurs introduced a more elaborate classification system for spiral galaxies (→ spiral galaxy) based on three morphological characteristics:
1) Bars. Galaxies are divided on the basis of the presence or absence of a nuclear → stellar bar. SA denotes spiral galaxies without bars, complementing Hubble's use of SB for → barred spirals. De Vaucouleurs also defined an intermediate class, SAB, containing weakly barred spirals. → Lenticular galaxies are also classified as unbarred (SA0) or barred (SB0), with the notation S0 reserved for those galaxies for which it is impossible to tell if a bar is present or not.
2) Rings. Galaxies possessing ring-like structures are denoted (r), those without rings (s), and transition galaxies (rs).
3) Spiral arms. These are divided into the following subclasses: Sd (SBd), that is diffuse, broken arms made up of individual stellar clusters and nebulae; very faint central → bulge; Sm (SBm): irregular in appearance; no bulge component; and Im, that is highly irregular galaxy.
Galaxies in the classes Sm and Im are termed the → Magellanic spirals and irregulars, respectively. The → Large Magellanic Cloud is of type SBm, while the → Small Magellanic Cloud is an irregular (Im).

de Vaucouleurs radius; → system.

de-
  وا-، فرو-   
vâ- (#), foru- (#)

Fr.: de-   

A prefix occurring in loanwords from L. to indicate:
1) Opposition, reversal: decentralize, decode, deactivate, de-emphasis.
2) Removal from: dethrone.
3) Reduction, degradation: declass, devalue.
4) reversal: detract, detect.
5) Derivation from: derive, deverbative.

M.E., from O.Fr. de-, des-, partly from L. de- "from, down, away," and partly from L. → dis-.

Prefix vâ- denoting "reversal, opposition; separation; repetition; open; off; away," variant of bâz-, from Mid.Pers. abâz-, apâc-; O.Pers. apa- [pref.] "away, from;" Av. apa- [pref.] "away, from," apaš [adv.] "toward the back;" cf. Skt. ápāñc "situated behind."
Foru- "down, downward; below; beneath," Mid.Pers. frôt "down, downward," O.Pers. fravata "forward, downward," Skt. pravát- "a sloping path, the slope of a mountain."

de-excitation
  فرو انگیزش   
foru-angizeš

Fr.: désexcitation   

Transition from an excited energy state to a lower energy level, as in spectral line formation or particle emission from an atomic nucleus.

From → de- + → excitation.

de-orbit
  وامداریدن   
vâmadâridan

Fr.: désorbiter   

To cause a spacecraft to leave its operational orbit to enter a descent phase or to change course.

From → de- + → orbit.

de-orbiting
  وامدارش   
vâmadâreš

Fr.: désorbitage   

Of a spacecraft, the act or process of departing from an operational orbit. → de-orbit.

Noun form of → de-orbit.

de-projection
  وا-فراشانش   
vâ-farâšâneš

Fr.: déprojection   

A method for estimating the real orientation of a field and/or related velocities/separations from two-dimensional images.

de-; → projection.

<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu coa coe coh col col col com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos Cou cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis div dog Dop dou dra dua dus dwa dyn e-m ear ecl eco eff ein Ein elb ele ele ele ele Els emi emp ene enr env epi equ equ Eri est Euc eva evo exc exc exh exo exp exp ext ext f-n Fah fam fau fee Fer fib fil fin fir fix fle flu foc for for for fra fre fre fri fun fuz gal gal gal Gan gau GCN gen geo geo geo geo Gl glo gra gra gra gra gra gre gro GW1 hab hal han HAR haz hea hel hel Hen Her heu Hig Hil hol hop hor hou Hub Hum Hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind ine inf inf inf inh INP ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos Jun K2 Kep key kin Kol lag lam Lan lar las lav lea leg len lev lig lim lin lin lin lis lob loc log lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal mar mas mas mat max mea mea mee Men mer met met met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxy pal pan par Par par par pas pea Pen per per per per per pet pha pho pho pho phy pie Pit Pla pla pla pla ple Poi pol pol pol pol pop pos pos pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sah san Sat sca Sch Sch scr sec sec sec sei sel sem sep set sha she sho sid sig sil sim sin sit sky slu sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spl spr sta sta sta sta sta ste ste sti sto str str sub sub sub sug sun sup sup sup sup sur syl syn sys tal Tay tel ten ter tex the the the thi tho thu tid tim tod top tot tra tra tra tra tri tri tro tru tur twi Typ UFO ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yel you zer zod > >>