An Etymological Dictionary of Astronomy and Astrophysics

1. To get away; to get free of.
   

2. An act or instance of escaping.

Etymology (EN): 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.”

Etymology (PE): 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”).

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: V_e = (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. The escape velocity from the Sun is about 618 km s^-1, and the solar escape velocity from Earth’s orbit is about 42.1 km s^-1.

See also: → escape; → velocity.

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).

See also: Short for Echelle Spectro-Polarimetric Device for the O bservation of Stars; → echelle; → spectro-; → polarimetric; → device; → observation; → star.

1. To found, institute, build, or bring into being on a firm or stable basis.
   

2. To show to be valid or true; prove.

Etymology (EN): 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”).

Etymology (PE): 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.”

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 (Dictionary.com).

See also: → establish; → -ment.

1. Favorable opinion or judgment; respect or regard.
   

2. To regard highly or favorably; regard with respect or admiration (Dictionary.com).

Etymology (EN): M.E. estemen, from M.Fr. estimer, from L. aestimare “to value, determine the value of, appraise,” → estimate.

Etymology (PE): Arj “esteem, honor, dignity; price, worth, value,” → credit. Arj nehâdan with nehâdan “to place, put,” → position.

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

See also: → esteem; → -able.

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

2. Verb of estimate.

Etymology (EN): From M.Fr. estimer, from L. æstimatus, p.p. of æstimare “to value, estimate.”

Etymology (PE): 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.

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

See also: 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.

See also: 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.
   

2. An arm or inlet of the sea at the lower end of a river (Dictionary.com).

Etymology (EN): 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.”

Etymology (PE): Kešandân, literally “site of tides,” from kešand, → tide,

• -ân a suffix of place and time.