An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -oi obj obs obs oce Of? ohm on- ope opi opt opt orb orb org Ori ort Ost ove oxi > >>

Number of Results: 394
Ostriker-Peebles criterion
  سنجیدار ِ استرایکر-پیبلس   
sanjidâr-e Ostriker-Peebles

Fr.: critère d'Ostriker-Peebles   

An approximate empirical criterion for the stability of a → galactic disk against its collapse to form a bar. The disk is stable if the following relation holds: T/|W| < 0.14, where T is the rotational → kinetic energy and |W| is the absolute value of the gravitational → potential energy. While the → Toomre criterion applies only to small linear perturbations, the Ostriker-Peebles criterion describes global modes.

Ostriker & Peebles, 1973, ApJ 186, 467; → criterion.

  برون، اُس-   
borun, os-

Fr.: hors   

Away from, or not in, the normal or usual place, position, state, etc.

O.E. ut; (cf. O.N., O.Fris., Goth. ut, Du. uit, Ger. aus; PIE base *ud- "up, up away" (cf. Pers. os-, as below; Gk. hysteros "the latter;" L. usque "all the way to, without interruption;" O.Ir. ud- "out;" Rus. vy- "out").

Borun, variant birun "out, the outside," from Mid.Pers. bêron, from "outside, out, away," variant bêg, as in bêgânag (cf. Sogh. bêk "out, outside, apart, except," bêk-dênê "heretic," literally "out of religion") + rôn "side, direction;" Av. ravan- "(course of a) river").
Os-, from Mid.Pers. us-, uz-; Av. uz-, us- "out of, outside, from;" O.Pers. ud- (ud-apatatā "to rise up, rebel"), also Pers. preposition az "from; of; out of," prefixes zo- (in zodudan "to polish, clean;" Mid.Pers. uzdâtan; Av. uzdā-, from uz- + dā- "to make, create"), âz- (âzmâyeš, → experiment), haz- (haziné "cost, expenditure;" Mid.Pers. uzên, uzênak, from *uz-ayana- "going out;" Av. us- + ay- "to go" (→ assembly); PIE *ud- "up, out," cf. Skt. úd "up, away, out;" E. out, as above.

out of phase
  نافاز، ناهم‌فاز   
nâfâz, nâ-ham-fâz

Fr.: déphasé   

The condition of two oscillators that have the same frequency but different phases. Opposed to → in phase.

out; → phase.

  ا ُسبلک   

Fr.: sursaut   

1) A fairly brief period of unusually strong gas and/or dust production from a comet nucleus.
2) A brief period of enhancement of emission from a star, a quasar, etc.

out; → burst.

outburst decay
  تباهی ِ اسبلک   
tabâhi-ye osbelk


A phase in the → light curve evolution of eruptive objects such as → dwarf novae, → Soft X-ray Transients, and transient → magnetars which follows the characterized sudden increase in their flux (over a factor ~ 1000 over the quiescent level). Outburst decay is slow and lasts months or years.

outburst; → decay.

borunšod (#)

Fr.: issue, résultat   

A final product or end result; consequence; issue (

out; → come.

Borunšod "outcome," from borun, → out, + šod, šodan "to go, to pass, to change," → become.

borunzad (#)

Fr.: affleurement   

Emergence of a particular rock-body, e.g. a stratium or vein, at the ground surface. Outcrops can be formed naturally or by human action. Stream erosion and highway construction can produce outcrops.

Noun use of crop out, from crop, from M.E., O.E. cropp "bird's craw," also "head or top of a sprout or herb;" → out.

Borunzad, literally "strike out," from borun, birun, → out, + zad, zadan "to strike, beat," from Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *gwhen- "to strike, kill."

biruni (#)

Fr.: externe   

Being or located on or toward the outside; external.

out + -er suffix of comparative degree of adjectives.


outer core
  مغزه‌ی ِ بیرونی   
maqze-ye biruni

Fr.: noyau externe   

The upper zone of the → Earth's core, just below the → mantle, extending from a depth of about 2900 km to 5100 km. It is presumed to be → liquid because it sharply reduces → compressional wave velocities and does not transmit → shear waves. Its density is from 9 to 11 g/cm3. The → temperature ranges from 4400 °C in the outer areas to 6100 °C near the → inner core. Since shear waves do not propagate through a fluid, the Earth's outer core is considered to be liquid because the shear wave velocity is zero. Convection motion within the outer core, along with the rotation of the Earth creates an effect that maintains the Earth's → magnetic field.

outer; → core.

outer Lindblad resonance (OLP)
  باز‌آوایی ِ لیندبلاد ِ برونی   
bâzâvâyi-ye Lindblad-e boruni

Fr.: résonance de Lindblad externe   

A → Lindblad resonance expressed by: Ωp = Ω + κ/m.

outer; → Lindblad resonance.

outer planet
  سیاره‌یِ بیرونی   
seyyâre-ye biruni (#)

Fr.: planète extérieure   

A planet that revolves around the Sun beyond the → asteroid belt, namely → Jupiter, → Saturn, → Uranus, and → Neptune.

out; → planet.

outer space
  فضا، برون-فضا، فضای ِ بیرونی   
fazâ, borun-fazâ, fazâ-ye biruni

Fr.: espace, espace extra-atmosphérique   

The space beyond the Earth's atmosphere.

outer; → space.

  ا ُستچان   

Fr.: flot, écoulement   

The act of flowing out; a fluid that flows out; any outward movement. Opposite of → inflow.

out + → flow.

  ا ُسگازش   

Fr.: dégazage   

1) General: The slow release of a gas that was trapped, frozen, absorbed or adsorbed in some material.
2) Planets: Release of the gases locked in the interior of a planet during volcanic activity so that they become part of the planet's atmosphere.

out + verbal noun from → gas.

borundâd (#)

Fr.: sortie   

1) Power which is given out by any plant or part of such plant, in the form and for the purpose required.
2) Computers: The information produced by a program or process from a specific → input.

From → out + put, from M.E. put(t)en "to push, thrust, put;" O.E. *putian.

borundâd, from borun, birun, → out, + dâd "given," p.p. of dâdan "to give" (Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," akin to L. data, → datum).

  برون‌رسانی، همه‌آموزی   
borun-rasâni, hame-âmuzi

Fr.: éducation grand public   

The act of extending research activities beyond its current or conventional limits to a wide section of the population for educational purposes.

out; reach, M.E. rechen, O.E. ræcan "to extend, hold forth;" cf. O.Fris. reka, M.Du. reiken; cognate with Pers. râst, → right.

Borun-rasâni, from borun, → out, + rasâni verbal noun of rasândan "to carry, guide, send," transitive of rasidan "to reach, arrive," → access.
Hame-âmuzi, literally "teaching every body," from hamé, → all; âmuzi, from âmuxtan "to teach; learn," → teach.


Fr.: externaliser   

To obtain under contract with an outside supplier.

out; → source.


Fr.: externalisation   

The transferring of certain business functions from internal staff to outside contractors.

Verbal noun from → outsource.

xâgi (#)

Fr.: ovale   

Having the general form, shape, or outline of an egg; ellipsoidal or elliptical.

From M.L. ovalis "egg-shaped," from L. ovum "egg," cognate with Pers. xâg, as below.

Xâgi "egg-shaped," literally "pertaining to an egg," from xâg "egg," Lori, Laki , Pash. "egg," Ossetic ajk "egg," Khotanese āhaa- "egg;" variant xâyé "egg; testicle;" Mid.Pers. xâyak "egg;" Av. aēm/aiam "egg;" cf. Gk. oion, L. ovum, as above; Goth. ada; O.E. æg; Ger. Ei; PIE *owyo-/*oyyo- "egg."

  بیش-، ا َبَر   
biš-, abar-

Fr.: trop, très, en plus; par-dessus, partout   

A prefixal use of over with the sense of "over the limit," "to excess," "too much" to form verbs, adjectives, adverbs, and nouns, e.g. → overabundance; → overdense; → overestimate.

O.E. ofer, from P.Gmc. *uberi (cf. O.S. obar, O.Fris. over, O.H.G. ubar, Ger. über, Goth. ufar "over, above"), from PIE *uper; cf. Gk. hyper, preposition and adverb, "over, beyond, overmuch, above;" cognate with L. super- and Pers. abar-, as below.

Biš- "much, more; in excess; great" (from Mid.Pers. veš "more, longer; more frequently," related to vas "many, much" (Mod.Pers. bas); O.Pers. vasiy "at will, greatly, utterly;" Av. varəmi "I wish," vasô, vasə "at one's pleasure or will," from vas- "to will, desire, wish").
Abar, variant 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").

<< < -oi obj obs obs oce Of? ohm on- ope opi opt opt orb orb org Ori ort Ost ove oxi > >>