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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1381
spectral type
  گونه‌ی ِ بینابی   
gune-ye binâbi

Fr.: type spectral   

A group into which stars may be classified according to the characteristics of their spectra. Spectral type correlates with the star's → effective temperature and → color. There are seven main spectral types. From hot and blue to cool and red, they are O, B, A, F, G, K, and M. Each spectral type is divided into several subtypes. For example, from warmest to coolest, spectral type G is G0, G1, G2, G3, and so on to G9. A precise → spectral classification requires determining the → luminosity class. The Sun is spectral type G2 V.

spectral; → type.

spectral variability
  ورتندگی ِ بینابی   
vartandegi-ye binâbi

Fr.: variabilité spectrale   

The state of a spectrum from an astronomical object in which the lines change with time as far as their intensity, profile, and wavelength are concerned.

spectral; → variability.

spectro-
  بیناب-   
binâb- (#)

Fr.: spectro-   

A combining form representing → spectrum in compound words.
spectrogram, → spectrograph, → spectroheliogram, → spectroheliograph, → spectrometer, → spectrophotometer, → spectropolarimeric, → spectropolarimetry, → spectroscope, → spectroscopy, → spectroscopic.

spectrum

Spectro-Polarimetric High-contrast Exoplanet (SPHERE)
     

Fr.: Spectro-Polarimetric High-contrast Exoplanet (SPHERE)   

The → extreme adaptive optics system and → coronagraphic facility at the → European Southern Observatory (ESO) → Very Large Telescope (VLT) (UT3) available from May 2014. Its primary science goal is imaging, low-resolution spectroscopic, and polarimetric characterization of → exoplanetary system at → visible and → near-infrared wavelengths (0.5-2.32 μm). SPHERE is capable of obtaining → diffraction-limited images at 0''.02 to 0''.08 resolution depending on the wavelength. Its → spectral resolution is 30 to 350, depending on the mode.

spectro-; → polarimetric; → high; → contrast; → exoplanet.

spectrogram
  بیناب-نگاشت   
binân-negâš (#)

Fr.: spectrogramme   

A plot of the intensity of light at different wavelengths obtained using a spectrograph.

spectro-; → -gram.

spectrograph
  بیناب-نگار   
binâb-negâr (#)

Fr.: spectrographe   

An instrument that disperses the light into spectral lines and records them.

spectro-; → -graph.

spectroheliogram
  هور-بیناب‌نگاشت   
hur-binâbnegâšt

Fr.: spectrohéliogramme   

An image of the Sun taken in the light of one particular wavelength.

spectro-; → heliogram.

spectroheliograph
  هور-بیناب‌نگار   
hur-binâbnegâr

Fr.: spectrohéliographe   

An instrument for recording monochromatic images of the Sun.

spectro-; → heliograph.

spectrometer
  بیناب‌سنج   
binâb-sanj

Fr.: spectromètre   

1) A spectrograph in which the spectrum is recorded by electronic means so that wavelength, intensity, etc. can be measured.
2) An instrument for determining the distribution of energies in a beam of particles.

spectro-; → -meter.

spectrophotometer
  بیناب-نورسنج   
binâb-nursanj

Fr.: spectrophotomètre   

An instrument designed to measure the intensity of a particular spectral line or a series of spectral lines.

spectro-; → photometer.

spectrophotometric
  بیناب-شیدسنجیک   
binâb-šidsanjik

Fr.: spectrophotométrie   

Of or relating to → spectrophotometry.

spectrum; → photometry.

spectrophotometry
  بیناب-شیدسنجی   
binâb-šidsanji

Fr.: spectrophotométrie   

In astronomy, measurement of the absolute fluxes of the components of different frequencies in the spectrum of a light source.

spectrum; → photometry.

spectropolarimetric
  بیناب-قطبش‌سنجی، بیناب-قطبش‌سنجیک   
binâb-qotbešsanji, binâb-qotbešsanjik

Fr.: spectropoolarimétrique   

Of or relating to → spectropolarimetry.

spectropolarimetry; → -ic.

spectropolarimetry
  بیناب-قطبش‌سنجی   
binâb-qotbešsanji

Fr.: spectropolarimétrie   

A technique of observation in → astrophysics which combines → spectroscopy and → polarization measurements. Spectropolarimetry has a wide range of applications in astrophysics, including → stellar magnetic field studies. → ESPaDOnS, → HARPSpol.

spectro-; → polarimetry.

spectroscope
  بیناب-نما   
binâb-nemâ (#)

Fr.: spectroscope   

An optical instrument for forming and examining the spectrum of a light source. The instrument contains a narrow slit through which the light enters. The slit is placed at the focus of a positive lens called the collimator lens to form a beam of parallel rays. The beam of light falls on a dispersing element (prism, grating, or grism) which separates the light into its colors. This spectrum can be observed with an ocular (in the spectroscope) or recorded on a detector (in the spectrograph).

spectro-; → -scope.

spectroscopic
  بیناب‌نمایی، بیناب‌نماییک   
binâbnemâyi, binâbnemaayik

Fr.: spectroscopique   

Of or relating to → spectroscopy.

spectro-; → -scopy; → -ic.

spectroscopic binary
  دُرین ِ بیناب‌نمایی   
dorin-e binâbnemâyi

Fr.: binaire spectroscopique   

A binary system that cannot be resolved by a telescope, but can be identified by means of the Doppler shift of the spectral lines. As stars revolve, they alternately approach and recede in the line of sight. This motion is shown up in their spectra as a periodic oscillation or doubling of spectral lines.

spectroscopic; → binary.

spectroscopic degeneracy
  واگنی ِ بیناب‌نمایی   
vâgeni-ye binâbnemâyi

Fr.: dégénérescence spectroscopique   

The situation in which spectroscopic features in a certain optical region are not sensitive enough to distinguish adjacent → luminosity classes, for instance → dwarf stars from → giant stars.

spectroscopic; → degeneracy.

spectroscopic Hertzsprung-Russell diagram (sHRD)
  نمودار ِ بینابنماییک ِ هرتسپرونگ-راسل   
nemudâr-e binâbnemâyik-e Hertzsprung--Russell

Fr.: diagramme spectroscopique de Hertzsprung-Russell   

A spacial → Hertzsprung-Russell diagram (HRD) which is independent of distance and extinction measurements. The sHRD is derived from the classical HRD by replacing the luminosity (L) to the quantity ℒ = T 4eff/g which is the inverse of the flux-weighted gravity introduced by Kudritzki et al. (2003). The value of ℒ can be calculated from stellar atmosphere analyses without prior knowledge of the distance or the extinction. In contrast to the classical Teff-log g diagram (→ Kiel diagram), the sHRD sorts stars according to their proximity to the → Eddington limit, because ℒ is proportional to the Eddington factor Γ = L/LEdd according to the relation ℒ = (1/4πσG)(L/M) = (c/(σκ)Γ, where σ is the → Stefan-Boltzmann constant, κ is the electron → scattering  → opacity in the stellar envelope, and the other symbols have their usual meanings (Langer, N., Kudritzki, R. P., 2014, A&A 564, A52, arXive:1403.2212, Castro et al., 2014, A&A 570, L13.

spectroscopic; → H-R diagram.

spectroscopic mass
  جرم ِ بیناب‌نمایی   
jerm binâbnemâyi

Fr.: masse spectroscopique   

The stellar mass derived from → gravity (g) and radius (R), expressed by M = gR2/G, where G is the → gravitational constant. Spectroscopic mass conveys the actual mass of the star, in contrast with its → initial mass.

spectroscopic; → mass.

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