An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < abs Hug > >>

Number of Results: 36 Search : curve
Hugoniot curve
  خم ِ هوگونیو   
xam-e Hugoniot

Fr.: courbe de Hugoniot   

A curve, on the pressure versus specific volume plane, representing the locus of all the possible states that can be reached by a substance immediately after the passage of a single → shock wave. For each initial condition there is a different curve. No combustion occurs in the process and, therefore, the chemical composition of the medium does not change. See also → Rayleigh line; → Crussard curve.

Named after the French physicist Pierre Henri Hugoniot (1851-1887), who worked on fluid mechanics, especially flow properties before and after shock waves; → curve.

interstellar reddening curve
  خم ِ سُرخش ِ اندر-اختری   
xam-e sorxeš-e andaraxtari

Fr.: courbe de rougissement interstellaire   

A graph showing the relation between → interstellar absorption (in magnitudes) and wavelength.

interstellar; → reddening; → curve.

Keplerian rotation curve
  خم ِ چرخش ِ کپلری   
xam-e carxeš-e Kepleri (#)

Fr.: courbe de rotation keplérienne   

A → rotation curve in which the speed of the orbiting body is inversely proportional to the → square root of its distance from the mass concentrated at the center of the system.

Keplerian; → rotation; → curve.

light curve
  نور-خم، خم ِ نور   
nur-xam, xam-e nur

Fr.: courbe de lumière   

1) A curve showing the behavior of the light from a → variable star over a period of time.
2) → supernova light curve.

light; → curve.

orbital phase curve
  خم ِ فاز ِ مداری   
xam-e fâz-e madâri

Fr.: courbe de la phase orbitale   

The photometric variability induced by the → orbital motion in a → two-body system.

orbital; → phase.

phase curve
  خم ِ فاز   
xam-e fâz

Fr.: courbe de phase   

1) Astro.: A curve describing the → brightness of a reflecting → natural satellite as a function of its → phase angle.
2) Math.: A plot of the solution to a set of equations of motion in a phase space as a function of time.

phase; → curve.

Planck curve
  خم ِ پلانک   
xam-e Planck

Fr.: courbe de Planck   

Same as → blackbody curve.

Planck; → curve.

potential energy curve
  خم ِ کاروژ ِ توند   
xam-e kâruž-e tavand

Fr.: courbe de l'energie potentielle   

A plot that displays the → potential energy of a moving body as a function of its position. It is explained by the → conservation of energy and the conversion of potential energy into → kinetic energy and vice versa.

potential; → energy; → curve.

probability curve
  خم ِ شوانایی   
xam-e šavânâyi

Fr.: courbe de probabilité   

A curve that describes the distribution of probability over the values of a random variable.

probability; → curve.

radial velocity curve
  خم ِ تندای ِ شعاعی   
xam-e tondâ-ye šo'â'i

Fr.: courbe de vitesse radiale   

A curve describing the variation of the radial velocity of a star, due to the Doppler effect, under the gravitational effect of a secondary body (companion or exoplanet). The amplitude of these variations depends upon the mass of the secondary and its distance from the star.

radial velocity; → curve.

regression curve
  خم ِ وایازش   
xam-e vâyâzeš

Fr.: courbe de régression   

A curve representing a non-linear relationship between two or more → variables.

regression, → curve.

response curve
  خم ِ پاسخ   
xam-e pâsox

Fr.: courbe de réponse   

A curve graphically representing the magnitude of the → response of a → detector to → radiation, usually as a function of → wavelength.

response; → curve.

rotation curve
  خم ِ چرخش   
xam-e carxeš

Fr.: courbe de rotation   

A plot of the variation in → orbital velocity of stars and → interstellar matter with distance from the center of a → galaxy. A "flat" rotation curve indicates that the mass of the galaxy increases linearly with distance from its center. See also: farsi→ Keplerian rotation curve

Rotation; → curve.

smooth curve
  خم ِ هموار   
xam-e hamvâr

Fr.: courbe lisse   

1) A curve which is free from abrupt fluctuations.
2) A curve if it has tangents at all points and the angle of inclination of the tangent is a continuous function of the arc length.

smooth; → curve.

supernova light curve
  خم ِ نور ِ اَبَرنووا، ~ ~ اَبَر-نو‌اختر   
xam-e nur-e abarnovâ, ~ ~ abar-now-axtar

Fr.: courbe de lumière de supernova   

The graph of luminosity as a function of time after a → supernova explosion. The → light curve goes up rapidly to a → peak luminosity, then decays away slowly over time, with different rates, depending on the → supernova type. The temporal evolution of a supernova's luminosity contains important information on the physical processes driving the explosion. The observed → bolometric light curves provide a measure of the total output of converted radiation of → Type Ia supernovae, and hence serve as a crucial link to theoretical models of the explosion and evolution.

supernova; → light; → curve.

velocity curve
  خم ِ تندا   
xam-e tondâ

Fr.: courbe de vitesse   

A plot of the radial velocity of an object against time, derived from the Doppler shift of spectral lines.

velocity; → curve.

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