An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

In → adaptive optics, eliminating the effects of atmospheric turbulence on the wavefront of the object being observed. → wavefront distortion.

→ wavefront; → correction.

The disruption of the spherical shape of a wavefront due to atmospheric turbulence which makes the adjacent points in the wavefront out of phase.

→ wavefront; → distortion.

In adaptive optics, a device that analyzes the light sample coming from the wavefront and determines the error in each part of the beam. The wavefront sensor used in adaptive optics is a → Shack-Hartmann type, which works in conjunction with a deformable mirror.

→ wavefront; → sensor.

The average slope in both the X and Y directions of a → wavefront or phase profile across the pupil of an optical system.

→ wavefront; → tilt.

Any transmission medium, such as a hollow metal conductor, coaxial cable, or glass fiber, capable of confining and supporting the propagation of electromagnetic waves regardless of wavelength or mode of propagation.

→ wave; guide, M.E., from O.Fr. guider "to guide, lead," from Frankish *witan "show the way," from P.Gmc. *wit- "to know" (cf. Ger. weisen "to show, point out," wissen "to know;" O.E. witan "to see"). Cognate with Pers. bin- "to see" (present stem of didan "to see"); Mid.Pers. wyn-; O.Pers. vain- "to see;" Av. vaēn- "to see;" Skt. veda "I know;" Gk. oida "I know," idein "to see;" L. videre "to see;" PIE base *weid- "to know, to see."

Mowjbar, from mowj, → wave, + -bar "carrier," from bordan "to carry, lead" (Mid.Pers. burdan, O.Pers./Av. bar- "to bear, carry," barəθre "to bear (infinitive)," Skt. bharati "he carries," Gk. pherein, L. fero "to carry;" PIE base *bher- "to carry").

The distance between two successive points in the wave that are characterized by the same phase of oscillation; e.g. → de Broglie wavelength; → Compton wavelength; → blaze wavelength; → peak wavelength; → center wavelength; → central wavelength; → cutoff wavelength.

→ wave; → length.

A small wave; ripple.

→ wave + -let a diminutive suffix.

A refinement of → Fourier analysis which enables to simplify the description of a complicated function in terms of a small number of coefficients. The formal history of wavelet theory began in the early 1980s when Jean Morlet, a French geophysicist, introduced the concept of wavelet and studied wavelet transform as a new tool for scientific signal analysis. In 1984, his collaboration with Alex Grossmann yielded a detailed mathematical study of the continuous wavelet transforms and their various applications. Although similar results had already been obtained 20-50 years earlier by several other researchers, the rediscovery of the old concepts provided a new method for decomposing functions.

→ wavelet; → theory.

1) A substance that is secreted by bees and is used by them for constructing the honeycomb, that is a dull yellow solid plastic when warm, and that is composed of a mixture of esters, cerotic acid, and hydrocarbons; called also beeswax.
2) Any of various substances resembling the wax of bees (Merriam-Webster.com).

M.E. waxen, O.E. weaxan; cognate with Du. was, Ger. Wachs.

Mum "wax; wax-candle."

Increasing in extent, quantity, intensity, power, etc.

Waxing, from wax, from M.E. wax "to grow bigger, greater;" O.E. weaxan "to increase, grow;" cf. O.H.G. wahsan, O.N. vaxa, Du. wassen, Ger. wachsen "to grow, increase;" cognate with Mid.Pers. waxš-, waxšidan "to grow;" Av. xaxš- "to grow," xaxša- "growth;" Skt. vaks- "to grow, become big;" Gk. auxein "to increase."

Fazâyandé "waxing, incresing," from fozudan, variant of 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- "press forward;" Av. gav- "to hasten, drive;" Sk. jav- "to press forward, impel quickly, excite," javate "hastens").

The phase of the Moon between the → new moon and the → first quarter which first appears in the evening.

→ waxing; → crescent.

The oval shape of the Moon a few days after the → first quarter.

→ waxing; → gibbous.

The circumstance when the phase of the Moon is increasing from → new moon to → full moon.

→ waxing; → moon.

A road, track, or path.

M.E. wei(gh)e, wai, from O.E. weg "road, path;" cf. Du. weg, O.H.G. weg, Ger. Weg, Goth. wigs "way;" PIE base *wegh- "to move."

Râh "way, path" (from Mid.Pers. râh, râs "way, street," also rah, ras "chariot;" from Proto-Iranian *rāθa-; cf. Av. raθa- "chariot;" Skt. rátha- "car, chariot," rathyā- "road;" L. rota "wheel," rotare "to revolve, roll;" Lith. ratas "wheel;" O.H.G. rad; Ger. Rad; Du. rad; O.Ir. roth; PIE *roto- "to run, to turn, to roll");

A → Wolf-Rayet star whose spectrum is dominated by emission lines of ionized carbon: C III 5696 Å, C III / C IV 4650 Å, C IV 5801-12 Å. This type is divided in sub-types WC4 to WC9.
For theoretical models, a Wolf-Rayet star whose carbon abundance at surface is larger than nitrogen abundance and has the abundance ratio (C + O) / He < 1 (in number).

W short for Wolf-Rayet star, C for → carbon.

A → WC Wolf-Rayet that its spectrum shows the following emission line characteristics: strong C IV 5801-12 Å, weak or absent C II 4267 Å, and moderate O V 5572-98 Å.

W, from → Wolf-Rayet; C, from → carbon; → star.

A → WC Wolf-Rayet whose spectrum shows the following emission line characteristics: C III 5696 Å very weaker than C IV 5801-12 Å and C III weaker than O V 5572-98 Å.

W, from → Wolf-Rayet; C, from → carbon; → star.

A → WC Wolf-Rayet whose spectrum shows the following emission line characteristics: C III 5696 Å very weaker than C IV 5801-12 Å and C III stronger than O V 5572-98 Å.

W, from → Wolf-Rayet; C, from → carbon; → star.

A → WC Wolf-Rayet with a spectrum shows the following emission line characteristics: C III 5696 Å weaker than C IV 5801-12 Å and C III very stronger than O V 5572-98 Å.

W, from → Wolf-Rayet; C, from → carbon; → star.

A → WC Wolf-Rayet with a spectrum shows the following emission line characteristics: C III 5696 Å stronger than C IV 5801-12 Å, C II 4267 Å absent, and O V 5572-98 Å weak or absent.

W, from → Wolf-Rayet; C, from → carbon; → star.