An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 647

Fr.: éruptif   

Relating to, formed by, characterized by, or producing → eruption.

eruption; → -ive.

eruptive object
  بر‌آخت ِ اسدرشی   
barÂxt-e osdareši

Fr.: objet éruptif   

An astronomical object such as a → variable star, a → nova, a → young stellar object, etc. characterized by abrupt changes of luminosity.

eruptive; → object.

eruptive prominence
  زبانه‌ی ِ اسدرشی   
zabâne-ye osdareši

Fr.: protubérance éruptive   

A huge solar prominence which has previously been quiescent but suddenly starts to lift up from the → photosphere with velocities of several hundred km/s and escapes into the → interplanetary space. Eruptive prominences with the highest velocities have been observed at 1300 km/s, reaching heights of 1 million km above the photosphere. Such prominences are often observed at the solar limb, in association with → coronal mass ejections. On the Sun's disk, the equivalent phenomenon is an eruptive filament.

eruptive; → prominence

eruptive variable
  ورتنده‌ی ِ اسدرشی   
vartande-ye osdareši

Fr.: variable éruptive   

same as → cataclysmic variable.

eruptive; → variable.

  ۱) گریختن، ۲) گریز   
1) gorixtan, 2) goriz (#)

Fr.: 1) échapper, s'échapper; 2) échapement   

1) To get away; to get free of.
2) An act or instance of escaping.

From M.E. escapen; O.Fr. eschaper, from V.L. *excappare, literally "to get out of one's cape, leave a pursuer with just one's cape," from L. → ex- "out" + L.L. cappa "mantle."

Gorixtan, goriz- "to escape; to flee, run away;" Mid.Pers. virextan; Proto-Iranian *vi-raik, from vi- "apart, asunder" + *raik; Av. raek- "to leave, set free, let off;" Mid./Mod.Pers. reg/rig (in mordé-rig "inheritance"); Skt. ric- "to leave," rinakti "gives up, evacuates;" Gk. leipein "to leave;" L. linquere "to leave;" from PIE *linkw-, from *leikw- "to leave behind" (cf. Goth. leihvan; O.E. lænan "to lend;" O.H.G. lihan "to borrow;" O.N. lan "loan").

escape velocity
  تندای ِ گریز   
tondâ-ye goriz

Fr.: vitesse d'échapement   

The speed an object must attain in order to free itself from the gravitational influence of an astronomical body. It is the minimum velocity for the object to enter a parabolic trajectory. The escape velocity is given by: Ve = (2GM/r)1/2, where G is the → gravitational constant, M is the mass of the astronomical body, and r is its radius. The escape velocity of the Earth is about 11.2 km s-1, that of the Moon is 2.4 km s-1, and that of the Sun about 618 km s-1.

escape; → velocity.

  نشاختن، نشازیدن   
nešâxtan, nešâzidan

Fr.: établir   

1) To found, institute, build, or bring into being on a firm or stable basis.
2) To show to be valid or true; prove.

From O.Fr. establiss-, stem of establir, from L. stabilire "make stable," from stabilis "firm, stable," literally "able to stand," from stare "to stand;" PIE base *sta- "to stand" (cf. Mod.Pers. istâdan "to stand;" O.Pers./Av. sta- "to stand, stand still; set;" Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh;" stasis "a standing still;" Lith. statau "place;" Goth. standan; O.E. standan "to stand," stede "place").

Nešâxtan, nešâzidan "to establish; to fix in the ground, strengthen," from ne- "down, below," → ni-, + šâxtan, šâz-, variants of Mod./Mid.Pers. sâxtan, sâz- "to form, prepare, build, make," ultimately from Proto-Iranian *sac- "to fit, be suitable; to prepare."


Fr.: 1, 2, 3, 4) établissement; 4) les pouvoirs établis   

1) The act or an instance of establishing.
2) The state or fact of being established.
3) Something established; a constituted order or system.
4) (often initial capital letter) The existing power structure in society; the dominant groups in society and their customs or institutions (

establish; → -ment.

  ۱) ارج؛ ۲) ارج نهادن   
1) arj (#); 2) arj nehâdan

Fr.: 1) estime; 2) estimer   

1) Favorable opinion or judgment; respect or regard.
2) To regard highly or favorably; regard with respect or admiration (

M.E. estemen, from M.Fr. estimer, from L. aestimare "to value, determine the value of, appraise," → estimate.

Arj "esteem, honor, dignity; price, worth, value," → credit. Arj nehâdan with nehâdan "to place, put," → position.

arjmand (#)

Fr.: estimable, digne d'estime   

Worthy of esteem; deserving respect or admiration. Capable of being estimated (

esteem; → -able.

  ۱) بر‌آورد؛ ۲) بر‌آوردن، بر‌آورد کردن   
1) barâvard (#); 2) barâvardan (#), barâvard kardan (#)

Fr.: 1) estimation; 2) estimer   

1) Statistics: An indication of the value of an unknown quantity based on observed data.
2) Verb of estimate.

From M.Fr. estimer, from L. æstimatus, p.p. of æstimare "to value, estimate."

Barâvard from prefix bar- "on, upon, up," → on-, + âvard past stem of âvardan "to bring, to cause, to produce," → production; verb with infinitive suffix -dan and kardan "to do, make," → verb.

barâvari (#)

Fr.: estimation   

Statistics: The process by which sample data are used to indicate the value of an unknown quantity in a population.

Verbal noun of → estimate.


Fr.: estimateur   

Statistics: Any quantity calculated from the sample data which is used to give information about an unknown quantity in a population. For example, the sample mean is an estimator of the population mean.

Agent noun of → estimate.

kešandân (#)

Fr.: estuaire   

1) That part of the mouth or lower course of a river in which the river's current meets the sea's tide.
2) An arm or inlet of the sea at the lower end of a river (

From L. aestuarium "a tidal marsh, mud-beds covered by water at high tides; channel inland from the sea," from aestus "boiling (of the sea), tide, heat," from PIE *aidh- "to burn;" cognates: Gk aithein "to burn," Skt. inddhe "burst into flames," O.Irish aed "fire," O.H.G. eit "funeral pile."

Kešandân, literally "site of tides," from kešand, → tide, + -ân a suffix of place and time.

Eta Carinae
Eta Afzal

Fr.: Eta de la Carène   

The most luminous and the most extensively studied of → Luminous Blue Variables. Known also as HD 93308, it lies in the → Trumpler 16star cluster of the → Carina Nebula and is about 7,500 to 8,000 → light-years away. η Carina probably began its life as a → very massive star with an initial mass of about 150 → solar masses, and has a current estimated mass of about 90-100 solar masses. The difference has been lost in sudden giant eruptions in the past few thousand years. The so-called → Homunculus Nebula results from the mass ejection by η Carinae during its giant outburst around 1843 when it reached a magnitude of -1 and became the second brightest star in the southern sky. About 1880 it reached magnitude 7 and has remained at this level, although with fluctuations. The 1843 event ejected at least 12 solar masses of gas moving at speeds of up to 650 km s-1 with a kinetic energy of almost 1050 erg. The double-lobed remnant has a mass of about 2.5 solar masses. It is divided by a → torus of cold dust (110 K), about 5 → light-years in radius and 15 solar masses, which was ejected in an earlier event some 1000 years ago. There is strong evidence that η Carinae is a → binary system with a period of about 5.5 years and a projected separation less than 30 → astronomical units (about 0.013 arcsec). A colliding-wind binary is suggested by the → hard X-ray spectrum. The main component has an estimated → mass loss rate of 10-3 solar masses per year.

Eta (η), Gk. letter of alphabet; the → Carina constellation.

  باتیزاب‌کندن، اچیدن   
bâ tizâb kandan, ecidan

Fr.: graver à eau forte   

1) To cut, bite, or corrode with an acid or the like; engrave with an acid or the like, as to form a design in furrows that when charged with ink will give an impression on paper.
2) To produce (a design, image, etc.) by this method, as on copper or glass (
3) Astro.: To cut or corrode an → iron meteorite with a strong → acid to reveal its hidden → crystalline structure.

From Du. etsen, from Ger. ätzen "to etch," from O.H.G. azzon "to cause to bite, feed," ultimately from PIE root *ed- "to eat;" cf. Av. ad- "to eat;" Mod.Pers. âš "thick brew, soup" (from O.Pers. *āšyā-, Proto-Ir. *HasH- "to eat"); Skt. ad- "to eat;" Gk. edo "I eat;" Lith. edu "I eat;" O.Irish ithim "I eat;" O.E. etan, O.H.G. essan, Ger. essen "to eat."

Bâ tizâb kandan, literally "to dig with acid," from "with," tizâb "acid," kandan "to dig;" ecidan, from E. etch, cognate with Pers. âš, as above.

  تیزاب-کند، اچش   
tizâb-kand, eceš

Fr.: gravure à eau forte   

1) The act or process of making designs or pictures on a metal plate, glass, etc., by the corrosive action of an acid instead of by a burin.
2) An impression, as on paper, taken from an etched plate.
3) The design so produced (
4) The act or process of cutting a smooth cross section of a → meteorite with → acid to reveal its → crystal structure.

Verbal noun of → etch.

etân (#)

Fr.: éthane   

A colorless, odorless → hydrocarbon, C2H6, which occurs with → methane in natural gas.

From eth-, from → ethyl, + -ane a suffix used in names of hydrocarbons of the methane or paraffin series.

etanol (#)

Fr.: éthanol   

An → alcohol having molecular formula C2H5OH. It is a colorless inflammable liquid with a characteristic odor. Ethanol is produced by fermentation of sugar: C6H12O6 → 2 C2H5OH + 2 CO2. It is the active constituent of alcoholic beverages. It is used as a fuel and as a solvent in the extraction of specific substances. It is also known as → ethyl alcohol. Ethanol in the → interstellar medium was first detected toward the → Sagittarius B2 molecular cloud at 82.265, 90.118, and 104.809 GHz (B. Zuckerman et al. 1975, ApJ 196, L99).

Short for → ethyl alcohol.

eter (#)

Fr.: ether   

1) Physics: A hypothetical medium filling all space formerly postulated to account for the propagation of → electromagnetic radiation through space. In order to facilitate description and to provide a physical explanation of various phenomena involving action at a distance and electromagnetism, a medium had been postulated with mechanical properties adjusted to provide a consistent theory. In 1887 Michelson and Morley attempted to measure the motion of the Earth through the ether. No such motion was detected. The → Michelson-Morley experiment has been repeated under different conditions, but the hypothesis of a stationary ether through which the Earth moves is not verified.
2) The substance supposed by Aristotle to constitute stars and fill the outer space.
3) Chemistry: A family of organic compounds with the general formula R-O-R', where R and R' are hydrocarbon radicals. In particular diethyl ether, C2H5OC2H5, which is a volatile colorless liquid with a pleasant smell.

From L. æther "the upper air, pure air," from Gk. aither "upper air," from aithein "to burn, shine."

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