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 diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ Eri est Euc eva evo exc exc exh Exo exp exp ext ext f(R fac fam fat fee Fer Fib fig fin fir fix fle flu foc for for for fra fre Fre fri fun fuz Gal gal gal Gam gau Gay gen Geo geo geo geo gim glo gov gra gra gra gra gre gro Gun hab hal han Har haz hea hel hel Hen Her het Hig hil hol Hoo hor hou Hub hum hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind Ind inf inf inf inf inn ins ins int int int int int int int int inv ion ion Irr iso iso iso jan jit Jul jus Kel ker kin kni La lam lan Lap las lat Lay Led Len let lif lig lin lin lin liq Lit loc log lon lou low lum lun Lym M d Mag mag mag mag mag mag maj man mar mas mas mat mea mea mec mem mer Mes met met mho mic Mie Mil min mis MKS MOd mol Mon moo mot mul mul myo nak Nas nat neb neg neu neu New New nit noi non non nor nor nuc nuc nul nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi pai Pan par par Par par pas Pav Pel per per per per Per per pha phi pho pho pho phy Pip Pla pla PLA pla ple plu pol pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul pur qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea rea rec rec red red ref ref reg rel rel rel rep res res res res ret RHB rid rig ris roc Ros rot rub Rut Sag sam sat sca sca Sch sci Sea sec sec see sel sem sen set Sha sha shi shu sid sil sim sin SIS ski Slo smo Soc sol sol sol sol son sou spa spa spe spe spe sph spi spi Spo squ sta sta sta sta Ste ste ste sto str str str sub sub suc sun sup sup sup sup sur Swa syn syn tab tar tel tem ter tes the the the the Tho thr tid tim Tit top tot tra tra TRA tra tre tri tri tru Tun Tus tym Typ ult unb und uni uni uns upp Urs vac van var Vei Ven ver vic Vir vir vis vol W 4 war wat wav wea wed wet wid win WN2 Wol wri xen yok zen zin > >>

Number of Results: 12955 Search : far
envelope
  پوشه   
pušé (#)

Fr.: enveloppe   

A shell of dust or gas expanding out from an astronomical object such as a star or a comet's nucleus.

From Fr. enveloppe, from O.Fr. envoloper "to envelop," from en- "in" + voloper "wrap up," of obscure origin, perhaps related to M.L. aluppa "a very thin piece or slice of wood" and influenced by L. volvere "to roll."

Pušé, noun from pušidan "to cover; to put on;" Mid.Pers. pôšidan, pôš- "to cover; to wear;" cf. Mid.Pers. pôst; Mod.Pers. pust "skin, hide;" O.Pers. pavastā- "thin clay envelope used to protect unbaked clay tablets;" Skt. pavásta- "cover," Proto-Indo-Iranian *pauastā- "cloth."

environment
  ۱، ۲، ۳) پرگیر؛ ۳) زیستبوم   
1, 2, 3) pargir (#); 3) zistbum

Fr.: environnement   

1) An aggregate of surrounding → circumstances, → conditions, or → influences in which a thing is situated or is developed.
2) Computers: The entire set of conditions under which one operates a → computer, as it relates to the hardware, operating platform, or operating system.
3) Ecology: The totality of circumstances surrounding an → organism or group of organisms. More specifically, the combination of external physical conditions that affect and influence the growth, development, and survival of organisms.

From environ + -ment; the first component from Fr. environs, plural of O.Fr. environ "compass, circuit," from environ (adv.) "around," from en- "in" + viron "circle, circuit," from virer "to turn."

Pargir, from par- "around, surrounding," variant pirâ-circum- + gir agent noun and present stem of gereftan "to take, seize; to make prisoner; to intercept" (Mid.Pers. griftan; Av./O.Pers. grab- "to take, seize;" cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving;" M.L.G. grabben "to grab," from P.Gmc. *grab; E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").
Zistbum, from zist "life, existence," → bio-, + bum "region, land, place," → eco-.

epact
  بر افزا   
barafzâ

Fr.: épacte   

1) The time that must be added to the lunar year (12 lunations) to make it coincide with the solar year (about 11 days).
2) The moon's age at the beginning of the calendar year.

From Fr. épacte, from L. epacta, from Gk. epaktos, verbal adj. of epagein "to intercalate, add, bring forward," from epi "on" + ag-, from agein "to bring, to lead;" cf. L. agere "to drive, set in motion," → act.

Barafzâ, from bar- "on, upon, up" (Mid.Pers. abar; O.Pers. upariy "above; over, upon, according to;" Av. upairi "above, over," upairi.zəma- "located above the earth;" cf. Gk. hyper- "over, above;" L. super-; O.H.G. ubir "over;" PIE base *uper "over") + afzâ, afzudan "to add, increase" (Mid.Pers. abzudan "to increase, grow;" O.Pers. abijav- "to increase, add to, promote," from abi-, aiby- "in addition to; to; against" + root jav- "to press forward;" Av. gav- "to hasten, drive;" Sk. jav- "to press forward, impel quickly, excite," javate "hastens").

epagomena
  اندرگاه، تروفته، دزدیده   
andargâh (#), tarufté (#), dozdidé (#)

Fr.: épagomène   

In Old Iranian and Egyptian calendars and much later in the → French Republican Calendar, one of five (or six) days placed between the 30th of the last month and the first day of the new year to result in a fixed year of 365 (366) days every year; plural epagomenae. Same as → epagomenal day. See also → sansculottide.

From Gk. epagomenos "added," from epagein "to add, to intercalate," from → epi- "on" + agein "to bring, to lead," → act.

Andargâh "intercalary," literally "time between," from andar "between, among," → inter-, + gâh "time;" Mid.Pers. gâh; 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").
Tarufté "intercalary," literally "stolen (day);" Mid.Pers. truftag, from taruftan "to steal," traft "stolen;" Mod.Pers. Lârestâni dialect toftak "spy;" Av. tarəp- "to steal," tarəfiiāt- "he would steal;" cf. Skt. tarp- "to steal, rob," paśu.trp- "stealing cattle."
Dozdidé "intercalary," literally "stolen (day)," p.p. of dozdidan "to steal," Mid.Pers. duz(d)itan, from duzd "thief," from Av. duždāo- "miscreant, villain."

epagomenal day
  روز ِ اندرگاه، ~ تروفته، ~ دزدیده   
ruz-e andargâh (#), ~ tarufté (#), ~ dozidé (#)

Fr.: jour épagomène   

Same as → epagomena.

epagomena + → -al; → day.

ephemeris
  روزیج   
ruzij

Fr.: éphéméride   

A table of computed positions occupied by a celestial body over successive intervals of time such as daily; plural ephemerides.

From L. ephemeris "day book, diary," from Gk. ephemeris "diary, account book," from ephemeros "short-lived, lasting but a day," from → epi "on, upon" + hemerai, dative of hemera "day."

Ruzij, from ruz, → day + zij "astronomical table," from Mid.Pers. zig "astronomical table," originally "string," since the lines of a table were compared to strings used on a weaver's instrument, variant zih, meaning "cord, string" (Modern Persian zeh "cord, string"); Av. jiiā- "bow-string;" cf. Skt. jiyā- "bow-string;" PIE base *gwhi- "thread, tendon" (from which derive also Gk. bios "bow;" L. filum "thread;" Russ. žca "thread").

ephemeris day
  روز ِ روزیجی   
ruz-e ruziji

Fr.: jour des éphémérides   

86,400 → ephemeris seconds.

ephemeris; → day.

ephemeris meridian
  نیمروزان ِ روزیجی   
nimruzân-e ruziji

Fr.: méridien des éphémérides   

A fictitious meridian that rotates independently of the Earth at the uniform rate implicitly defined by → Terrestrial Dynamical Time (TDT).

ephemeris; → meridian.

ephemeris second
  ثانیه‌ی ِ روزیجی   
sâniye-ye ruziji

Fr.: seconde des éphémérides   

The length of a tropical second (1/31,556,925.97474 of the tropical year) on 1900 January 0.5 → ephemeris time.

ephemeris; → second.

ephemeris time (ET)
  زمان ِ روزیجی   
zamân-e ruziji

Fr.: Temps des éphémérides   

The uniform time-scale used as the independent variable to calculate the orbits in the solar system prior to 1984. Ephemeris Time was adopted in 1960 to deal with irregularities in the → Earth's rotation that had been found to affect the course of mean solar time. The definition of Ephemeris Time is based on Newcomb's analytical theory of the Earth's motion around the Sun (Newcomb 1898), according to which the geometric mean longitude of the Sun with respect to the Earth-Moon barycenter is expressed by:
L = 279° 41' 48".04 + 129 602 768".13 T + 1''.089 T2,
where L refers to the → mean equinox of date while T measures time from noon 1900 January 0 GMT in Julian centuries of 36525 days. Ephemeris Time is therefore defined as the instant near the beginning of the calendar year A.D. 1900 when the mean longitude of the Sun was 279° 41' 48''.04, at which instant the measure of ET was 1900 January 0, 12h precisely. In this system the fundamental unit was the → ephemeris second, which was defined so that the → tropical year at the epoch 1900.0 should be exactly 31 556 925,9747 seconds of ephemerides. Ephemeris Time was inconvenient in many ways and was supeseded with the → Terrestrial Dynamical Time (TDT), whose fundamental unit is the SI second.

ephemeris; → time.

ephemeris transit
  گذر ِ روزیجی   
gozar-e ruziji

Fr.: transit au méridien des éphémérides   

The passage of a celestial body or point across the → ephemeris meridian.

ephemeris; → transit.

epi-
  اپی-   
api-

Fr.: épi-   

Prefix meaning "upon, at, close upon (in space or time), on the occasion of, in addition."

Gk. epi- "upon, at, close upon (in space or time), on the occasion of, in addition," cognate with O.Pers./Av. apiy-, aipi- "upon, toward, along; also; however;" Skt. api "also, besides."

Prefix api-, from O.Pers./Av. apiy-, aipi-, as above.

epicycle
  ۱) فلک ِ تدویر؛ ۲) اپی-چرخه   
1) falak-e tadvir (#); 2) apicarxé

Fr.: épicycle   

1) In → Ptolemaic system, a circular → orbit of a body around a point that itself orbits circularly another point. Such a system was formulated to explain some → planetary orbits in terms of → circular motions in a → geocentric cosmology.
2a) Math.: A circle that rolls, externally or internally on another circle, generating an → epicycloid or → hypocycloid.
2b) In → galactic dynamics models describing the → spiral arms, a → perturbation of simple circular orbits. → epicyclic theory.

epi-; → cycle.

1) Falak-e tadvir, from Ar. falak al-tadwir, from falak "sphere" + tadwir "causing to turn in a circle."
2) → epi-; → cycle.

epicyclic
  اپی-چرخه‌ای   
apicarxe-yi

Fr.: épicyclique   

Of or pertaining to an → epicycle.

epicycle; → -ic.

epicyclic frequency
  بسامد ِ اپی-چرخه‌ای   
basâmad-e apicarxe-yi

Fr.: fréquence épicyclique   

In the → epicyclic theory of Galactic rotation, the frequency at which a star in the → Galactic disk describes an ellipse around its mean circular orbit. The epicyclic frequency relates to the → Oort's constants. In the solar neighborhood the epicyclic frequency is about 32 km s-1 kpc-1.

epicyclic; → frequency.

epicyclic oscillation
  نوش ِ اپی-چرخه‌ای   
naveš-e apicarxe-yi

Fr.: oscillation épicyclique   

In a → disk galaxy, the motion of a star about the orbital → guiding center when it is displaced radially. See also → epicyclic frequency, → epicyclic theory.

epicyclic; → oscillation.

epicyclic theory
  نگره‌ی ِ اپی-چرخه‌ای   
negare-ye apicarxe-yi

Fr.: théorie épicyclique   

The theory that describes the Galactic dynamics, that is the orbits of stars and gas clouds in the → Galactic disk, as well as the spiral → density wave. Formulated by Bertil Lindblad (1895-1965), the epicyclic theory assumes that orbits are circular with small deviations. Star orbits are described by the superposition of two motions: i) a rotation of the star (epicenter) around the Galactic center at the circular angular velocity, Ω, and ii) a retrograde elliptical motion at → epicyclic frequency, κ. The epicyclic motion in the Galactic plane occurs in a retrograde sense to conserve → angular momentum. In general Ω and κ are different and, therefore, orbits do not close. However, seen by an observer who rotates with the epicenter, orbits are closed ellipses.

epicyclic; → theory.

epicycloid
  اپی-چرخزاد   
apicarxzâd

Fr.: épicycloïde   

A curve traced by a point of a circle that rolls on the outside of a fixed circle. This curve was described by the Gk. mathematicians and astronomer Hipparchus, who made use of it to account for the apparent movement of many of the heavenly bodies.

epi-; → cycloid.

Epimetheus
  اپیمتیءوس   
Epimeteus

Fr.: Épiméthée   

The fifth of → Saturn's known satellites. It has a mean radius of 55 x 69 km and orbits its planet at a mean distance of 151,422 km. It shares the same → horseshoe orbit with → Janus. Epimetheus was discovered by Richard L. Walker in 1966. Also known as Saturn XI.

In Gk. mythology, brother of → Prometheus and → Atlas, and husband of → Pandora. His task was to populate the Earth with animals.

epimorphism
  اپی-ریخت‌مندی   
api-rixtmandi

Fr.: épimorphisme   

A → morphism f : Y → X if, for any two morphisms u,v : X → Z, u f = v f  implies u = v.

epi-; → morphism.

<< < -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 diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ Eri est Euc eva evo exc exc exh Exo exp exp ext ext f(R fac fam fat fee Fer Fib fig fin fir fix fle flu foc for for for fra fre Fre fri fun fuz Gal gal gal Gam gau Gay gen Geo geo geo geo gim glo gov gra gra gra gra gre gro Gun hab hal han Har haz hea hel hel Hen Her het Hig hil hol Hoo hor hou Hub hum hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind Ind inf inf inf inf inn ins ins int int int int int int int int inv ion ion Irr iso iso iso jan jit Jul jus Kel ker kin kni La lam lan Lap las lat Lay Led Len let lif lig lin lin lin liq Lit loc log lon lou low lum lun Lym M d Mag mag mag mag mag mag maj man mar mas mas mat mea mea mec mem mer Mes met met mho mic Mie Mil min mis MKS MOd mol Mon moo mot mul mul myo nak Nas nat neb neg neu neu New New nit noi non non nor nor nuc nuc nul nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi pai Pan par par Par par pas Pav Pel per per per per Per per pha phi pho pho pho phy Pip Pla pla PLA pla ple plu pol pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul pur qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea rea rec rec red red ref ref reg rel rel rel rep res res res res ret RHB rid rig ris roc Ros rot rub Rut Sag sam sat sca sca Sch sci Sea sec sec see sel sem sen set Sha sha shi shu sid sil sim sin SIS ski Slo smo Soc sol sol sol sol son sou spa spa spe spe spe sph spi spi Spo squ sta sta sta sta Ste ste ste sto str str str sub sub suc sun sup sup sup sup sur Swa syn syn tab tar tel tem ter tes the the the the Tho thr tid tim Tit top tot tra tra TRA tra tre tri tri tru Tun Tus tym Typ ult unb und uni uni uns upp Urs vac van var Vei Ven ver vic Vir vir vis vol W 4 war wat wav wea wed wet wid win WN2 Wol wri xen yok zen zin > >>