# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 8 Search : effective
 effective   ا ُسکرمند   oskarmandFr.: effectif   Actually in operation or in force; concrete; real.M.E., from L. effectivus "practical," from effect(us), p.p. of efficere, → effect + -ivus "-ive."Oskarmand, from oskar, → effect + -mand possession suffix. effective aperture   دهانه‌ی ِ ا ُسکرمند   dahâne-ye oskarmandFr.: ouverture effective   Of an antenna, the ratio of the extracted power by the antenna to the power per unit area (power density) in the incident wave.→ effective; → aperture. effective Eddington parameter   پارامون ِ ادینگتون ِ اسکرمند   pârâmun-e Eddington-e oskarmandFr.: paramètre d'Eddington effectif   The effective value of the → Eddington parameter in a non-homogeneous system (porous opacity).→ effective; → Eddington limit; → parameter. effective focal length   درازا‌ی ِ کانونی ِ ا ُسکرمند   derâzâ-ye kânuni-ye oskarmandFr.: longueur focale effective   The focal length of an imaging system, which consists of several lenses or mirrors.→ effective; → focal length. effective gravity   گرانی ِ اُسکرمند   gerâni-ye oskarmandFr.: gravité effective   In a → rotating star, the sum of the → gravity and the → centrifugal acceleration. The effective gravity is a function of the rotation velocity (Ω) and the → colatitude (θ). At the pole (θ = 0°) and the equator (θ = 90°) the effective gravity is radial. See also → total gravity.→ effective; → gravity. effective radius   شعاع ِ ا ُسکرمند   šo'â'-e oskarmandFr.: rayon effectif   Of a galaxy, the distance from its center within which half of the total luminosity is included.→ effective; → radius. effective temperature   دمای ِ ا ُسکرمند   damâ-ye oskarmandFr.: température effective   A measure of the surface temperature of a star derived from the total emitted energy, assuming that the star is a → blackbody emitter (→ Stefan-Boltzmann law, → Planck's radiation law). See also → brightness temperature; → color temperature.→ effective; → temperature. effectiveness   اسکرمندی   oskarmandiFr.: effectivité   The degree to which goals are achieved and the extent to which posed problems are solved. Compare → efficiency.→ effective; → -ness.