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.
Fr.: variable éruptive
same as → cataclysmic variable.
1) gorixtan, 2) goriz (#)
Fr.: 1) échapper, s'échapper; 2) échapement
1) To get away; to get free of.
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").
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.
An advanced stellar → spectropolarimeter designed and built at the Observatoire Midi-Pyréenées and installed at the → Canada-France-Hawaii Telescope (CFHT). It can obtain a a complete optical spectrum, from 370 nm to 1050 nm, in a single exposure. Among its characteristics: resolving power 65 000 to 80 000; 12% peak throughput (telescope and detector included); continuum subtracted linear and circular polarization spectra of the stellar light (in polarimetric mode). ESPaDOnS is used to study a broad range of important problems in stellar physics: from → stellar magnetic fields to → accretion disks and → extrasolar planets; from inhomogeneities and differential rotation on stellar surfaces to activity cycles and magnetic braking; from microscopic diffusion to turbulence, convection, and circulation in stellar interiors; from abundances and pulsations in stellar atmospheres to stellar winds; from the early phases of stellar formation to the late stages of stellar evolution; from extended circumstellar environments to distant interstellar medium (Donati et al., 2006, Solar Polarization, ASP Conf. Series, 358, 362, eds. R. Casini, B. W. Lites).
1) To found, institute, build, or bring into being on a firm or stable basis.
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.
1) arj (#); 2) arj nehâdan
Fr.: 1) estime; 2) estimer
1) Favorable opinion or judgment; respect or regard.
M.E. estemen, from M.Fr. estimer, from L. aestimare "to value, determine the value of, appraise," → estimate.
Fr.: estimable, digne d'estime
Worthy of esteem; deserving respect or admiration. Capable of being estimated (Dictionary.com).
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.
From M.Fr. estimer, from L. æstimatus, p.p. of æstimare "to value, estimate."
Statistics: The process by which sample data are used to indicate the value of an unknown quantity in a population.
Verbal noun of → estimate.
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.
1) That part of the mouth or lower course of a river in which the river's current
meets the sea's tide.
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.
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 16→ star 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.
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.
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 bâ "with," tizâb "acid," kandan "to dig;" ecidan, from E. etch, cognate with Pers. âš, as above.
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
Verbal noun of → etch.
From eth-, from → ethyl, + -ane a suffix used in names of hydrocarbons of the methane or paraffin series.
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.
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.
From L. æther "the upper air, pure air," from Gk. aither "upper air," from aithein "to burn, shine."
Fr.: entraînement de l'éther
A hypothesis put forward to explain the null measurement of the → ether drift. According to this hypothesis, the Earth somehow drags the ether with it as our planet rotates on its axis and revolves around the Sun. However, the ether drag hypothesis contradicts results from several experiments, including the → aberration of starlight.