An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 18 Search : color
additive color
  رنگ ِ بردایشی   
rang-e bardâyeši

Fr.: synthèse additive   

Color created by mixing light rays of different colors. Combining all the color rays of light results in white light. See also → subtractive color.

additive; → color.

rang (#)

Fr.: couleur   

1) A visual sensation produced in the brain when the eye views various wavelengths or frequencies of light.
2) Short for → color index.
3) A property of → quarks required to distinguish the three basic quarks of which → baryons are composed. In all → hadrons, the quarks (red, green, blue) are combined in such a way as to yield a colorless overall particle.

From M.E. colour, from O.Fr. colur, from L. color "color, hue," from Old L. colos "a covering," from PIE *kel-os- "that which covers," from *kel- "to cover, conceal."

Rang, from Mid.Pers. rang "color" (abrang "splendor"), related to Mod.Pers. razidan "to color," raxš "a mixture of red and white," also the name of Rostam's horse (loan from Sogd.?), awrang "glory, beauty, throne;" Kurd. raš "black;" cf. Skt. raj- "to color, to become red;" Gk. rezein "to color;" PIE base *(s)reg- "to color, paint" (Cheung 2007).

color charge
  بار ِ رنگ   
bâr-e rang

Fr.: charge de couleur   

In the → standard model of particle physics, a property possessed by → quarks and → gluons that determine rules for how these particles may interact in the context of → quantum chromodynamics. Color charge is analogous to electromagnetic charge, but it comes in three types rather than two, which results in a different type of force, the → strong interaction. There are three pairs of colors and anti-colors, named red (anti-red), green (anti-green), and blue (anti-blue). The terminology has nothing to do with visible color. It is only a word that is used to designate three independent types of the strong charge characteristic.

color; → charge.

color excess
  فزونی ِ رنگ   
fozuni-ye rang,

Fr.: excès de couleur   

The difference between the observed → color index of a star and the intrinsic color index corresponding to its → spectral type. It indicates the modification brought to a color index by the → interstellar absorption.

color; excess, M.E., from O.Fr., from L. excessus "departure, going beyond," p.p. excedere "to depart, go beyond," from → ex- "out" + cedere "to go, yield."

Fozuni, from afzuni "excess," afzuni kardan "to exceed bounds," → add; → color.

color index
  دیشن ِ رنگ   
dišan-e rang

Fr.: indice de couleur   

The difference between the → apparent magnitude of a star measured at one standard wavelength and the apparent magnitude at another longer, standard wavelength, allowing the quantitative measure of a star's color.

color; → index.

color temperature
  دمای ِ رنگ   
damâ-ye rang

Fr.: température de couleur   

The temperature of that black-body which has the same spectral energy distribution in a limited spectral region, as the object under study has.

color; → temperature.

color transformation
  ترادیس ِ رنگ   
tarâdis-e rang

Fr.: transformation de couleur   

Empirical mathematical transformation applied to the observed magnitudes in order to convert them into a standard system, or into a different system.

color; → transformation.

color-color diagram
  نمودار ِ رنگ-رنگ   
nemudâr-e rang-rang (#)

Fr.: diagramme couleur-couleur   

A diagram based on two photometric colors usually representing the same class of astronomical objects.

color; → diagram.

color-color plot
  نمودار ِ رنگ-رنگ   
nemudâr-e rang-rang (#)

Fr.: diagramme couleur-couleur   

Fr.: diagramme couleur-couleur

Same as → color-color diagram.

color-luminosity diagram
  نمودار ِ رنگ-تابندگی   
nemudâr-e rang-tâbandegi

Fr.: diagramme couleur-luminosité   

A form of → Hertzsprung-Russell diagram in which the luminosity is the vertical axis and the → color index the horizontal axis.

color; → luminosity, → diagram.

color-magnitude diagram
  نمودار ِ رنگ-برز   
nemudâr-e rang-borz

Fr.: diagramme couleur-magnitude   

A form of → Hertzsprung-Russell diagram in which the visual absolute magnitude Mv is the vertical axis and the → color index the horizontal axis.

color; → magnitude, → diagram.

  رنگ سنجی   
rangsanji (#)

Fr.: colorimétrie   

The measurement and definition of unknown colors in terms of standard colors.

color; → -metry.

false color
  رنگ ِ زیف   
rang-e zif

Fr.: fausse couleur   

In imaging technique, assigning color to black and white images to differentiate features or convey information. → true color.

false; → color.

five-color system
  راژمان ِ پنج‌رنگه   
râžmân-e panj-rangé

Fr.: système à cinq couleurs   

A photometric system which uses five filters, from ultraviolet to the red part of the visual spectrum: U, B, V, R and I.

five; → color; → system.

intrinsic color
  رنگ ِ درونگین   
rang-e darungin

Fr.: couleur intrinsèque   

A → color not affected by → extinction.

intrinsic; → color.

Newton's color wheel
  چرخ ِ رنگ ِ نیوتن   
carx-e rang-e Newton

Fr.: disque de Newton   

The arrangement of the seven colors of the rainbow on a disk. When the disk rotates very fast, the eye cannot distinguish between individual colors and the disk is perceived as white. This apparatus demonstrates the discovery made by Newton (Opticks, 1704) that light is composed of seven colors.

Newton; → color; → wheel.

subtractive color
  رنگ ِ زیرکرششی   
rang-e zirkaršeši

Fr.: synthèse soustractive   

Color produced by mixing pigments rather than light. Mixing all of the subtractive colors together results in the color black. See also → additive color.

subtractive; → color.

two-color diagram
  نمودار ِ دو رنگ   
nemudâr-e do rang

Fr.: diagramme deux couleurs   

A graph on which two color indices such as B-V and U-B are plotted, one along each axis, for a sample of stars or other objects, such as stars.

two; → color; → diagram.