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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu coa coe coh col col col com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos Cou cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ Eri est Euc eva evo exc exc exh Exo exp exp ext ext f(R fac fam fat fee Fer Fib fig fin fir fix fle flu foc for for for fra fre Fre fri fun fuz Gal gal gal Gam gau Gay gen Geo geo geo geo gim glo gov gra gra gra gra gre gro Gun hab hal han Har haz hea hel hel Hen Her het Hig hil hol Hoo hor hou Hub hum hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind Ind inf inf inf inf inn ins ins int int int int int int int int inv ion ion Irr iso iso iso jan jit Jul jus Kel ker kin kni La lam lan Lap las lat Lay Led Len let lif lig lin lin lin liq Lit loc log lon lou low lum lun Lym M d Mag mag mag mag mag mag maj man mar mas mas mat mea mea mec mem mer Mes met met mho mic Mie Mil min mis MKS MOd mol Mon moo mot mul mul myo nak Nas nat neb neg neu neu New New nit noi non non nor nor nuc nuc nul nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi pai Pan par par Par par pas Pav Pel per per per per Per per pha phi pho pho pho phy Pip Pla pla PLA pla ple plu pol pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul pur qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea rea rec rec red red ref ref reg rel rel rel rep res res res res ret RHB rid rig ris roc Ros rot rub Rut Sag sam sat sca sca Sch sci Sea sec sec see sel sem sen set Sha sha shi shu sid sil sim sin SIS ski Slo smo Soc sol sol sol sol son sou spa spa spe spe spe sph spi spi Spo squ sta sta sta sta Ste ste ste sto str str str sub sub suc sun sup sup sup sup sur Swa syn syn tab tar tel tem ter tes the the the the Tho thr tid tim Tit top tot tra tra TRA tra tre tri tri tru Tun Tus tym Typ ult unb und uni uni uns upp Urs vac van var Vei Ven ver vic Vir vir vis vol W 4 war wat wav wea wed wet wid win WN2 Wol wri xen yok zen zin > >>

Number of Results: 12955 Search : far
red wing
  بال ِ سرخ   
bâl-e sorx

Fr.: aile rouge   

Of a spectral line profile, the → line wing with wavelengths longer than that of the emission or absorption peak.

red; → wing.

red-edge
  لبه‌ی ِ سرخ   
labe-ye soex

Fr.: bord rouge   

A rise in a planet's surface → reflectivity between red → absorbance and → near-infrared reflection due to → vegetation. The red-edge is one of the possible signs of life on distant → habitable  → exoplanets. Its presence is attributed to the chlorophyll molecule and leaf structure. The leaves of land plants reflect sunlight much more efficiently long-ward of this edge than they do in the visible. Although the red-edge position for Earth's vegetation is fixed at around 700-760 nm, that for exoplanets may not necessarily be the same (Takizawa et al., 2017, Nature Scientific Reports 7, Article number: 7561).

red; → edge.

redden
  ۱) سُرخیدن؛ ۲) سرخاندن   
1) sorxidan; 2) sorxândan

Fr.: 1) rougir; 2) faire rougir   

1) (v.intr.) Of a spectral line, to reduce in intensity due to absorption by interstellar dust grains.
2) (v.tr.) Of interstellar dust, to absorb the light that passes through it.

Infinitives from → red.

reddened star
  ستاره‌ی ِ سرخیده   
setâre-ye sorxidé

Fr.: étoile rougie   

A star whose light has undergone → reddening.

Reddened, p.p. of → redden; → star.

reddening
  سُرخش   
sorxeš

Fr.: rougissement   

The process by which light from an astronomical object grows red as it travels through interstellar dust. Dust scatters blue light more than red, thus leaving predominantly red light transmitted.

Verbal noun of → redden.

reddening coefficient
  همگر ِ سرخش   
hamgar-e sorxeš

Fr.: coefficient de rougissement   

A dimensionless quantity determined from the comparison of the observed → Balmer decrements with respect to the theoretical values for given physical conditions of electron temperature and density. The reddening coefficient at Hβ is defined as c(Hβ) = log (I(Hβ)/F(Hβ)), where I(Hβ) and F(Hβ) are → de-reddened and reddened fluxes respectively. Also called logarithmic extinction.

reddening; → coefficient.

reddening function
  کریای ِ سرخش   
karyâ-ye sorxeš

Fr.: fonction de rougissement   

The normalized interstellar extinction at a given wavelength. It is defined by f(λ) = A(λ)/A(Hβ) - 1, where A(λ) is the extinction at the given wavelength and A(Hβ) the extinction at Hβ, with f(Hβ) = 0. It is used to → de-redden observed fluxes: I(λ)/I(Hβ) = F(λ)/F(Hβ).10c(Hβ).f(λ), where I represents the flux in the absence of extinction and F the observed flux affected by extinction, c(Hβ) being the → reddening coefficient.

reddening; → function.

reddening parameter
  پارامون ِ سرخش   
pârâmun-e sorxeš

Fr.: paramètre de rougissement   

A dimensionless quantity characterizing the → interstellar extinction, defined by the total-to-selective extinction ratio: RV = AV/E(B-V). The typical value found for the reddening parameter in the Milky Way is RV ~ 3.1, but it is known to vary from one line of sight to another, from values as 2 to as large as 6. Very large → dust grains would produce extinction with RV → ∞.

reddening; → parameter.

reddening vector
  بُردار ِ سرخش   
bordâr-e sorxeš

Fr.: vecteur de rougissement   

A vector indicating the direction in which interstellar reddening moves the position of a star in a multi-dimensional space of color indices.

reddening; → vector.

redshift
  سرخ‌کیب   
sorxkib

Fr.: décalage vers le rouge   

A shift in the lines of an object's spectrum toward longer wavelengths. Redshift indicates that an object is moving away from the observer. The larger the redshift, the faster the object is moving. Redshift is expressed by z = Δλ/λ = v/c, where λ is the wavelength, Δλ the wavelength shift, v the velocity of the source relative to the observer, and c the → speed of light. When v approaches c, redshift is expressed by the → relativistic formula z = ((1 +v/c)/(1 - v/c))½ - 1.

red; → shift.

redshift space
  فضای ِ سرخ-کیب   
fazâ-ye sorx-kib

Fr.: espace de décalage vers le rouge   

The space corresponding to → redshift measurements, as contrasted with real space. See also → redshift space distortion

redshift; → space.

redshift space distortion
  چولگی ِ فضای ِ سرخ-کیب   
cowlegi-ye fazâ-ye sorx-kib

Fr.: distorsion dûe aux vitesses particulières sur la ligne de visée   

The distortion observed in → redshift space of → galaxy clusters caused by peculiar velocities of the members (→ peculiar velocity). In a perfectly homogeneous → Friedmann-Lemaitre Universe the redshifts would accurately measure radial distances from the observer, and the mapping from real space to redshift space would simply be an identity. In an inhomogeneous Universe the peculiar velocities associated with any inhomogeneous structure will introduce a distortion in this mapping (N. Kaiser, 1987, MNRAS 227, 1). See also: → fingers of God, → Kaiser effect.

redshift; → space; → distortion;.

redshift survey
  بردید ِ سرخ‌کیب   
bardid-e sorx kib

Fr.: relevé de décalages vers le rouge   

A survey of a large region of the sky to measure the redshifts of all the galaxies down to a certain limiting magnitude.

redshift; → survey.

redshift-distance relation
  بازانش ِ سرخ‌کیب-دورا   
bâzâneš-e sorxkib-durâ

Fr.: relation décalage vers le rouge-distance   

The correlation, first established by E. Hubble, between the cosmological recession velocities of galaxies and their distances.

redshift; → distance; → relation.

redshifted line
  خط ِ سرخ‌کیبیده   
xatt-e sorx kibideh

Fr.: raie décalée vers le rouge   

A spectral line whose wavelength does not coincide with its theoretical value and is shifted toward longer wavelengths.

red; → shift; → line.

reduce
  ۱) باز‌هاختن، باز‌هازیدن؛ ۲) کاستن   
1) bâzhâxtan, bâzhâzidan; 2) kâstan

Fr.: réduire   

1) To bring to a certain state, condition, arrangement, etc.
Math.: To change the denomination or form, but not the value, of (a fraction, polynomial, etc.).
Chem.: To add an electron to.
2) To bring down to a smaller extent, size, amount, number, etc.; synonymous with → decrease.

M.E. reducen "to lead back," from O.Fr. reducer, from L. reducere, from → re- "back" + ducere "to bring, to lead."

From bâz-, → re- + Mid.Pers. hâxtan, hâzidan "to lead, guide, persuade," Av. hak-, hacaiti "to attach oneself to, to join," cf. Skt. sacate "accompanies, follows," Gk. hepesthai "to follow," L. sequi "to follow;" PIE *sekw- "to follow."
Kâstan, → decrease.

reduced mass
  جرم ِ بازهازیده   
jerm-e bâhâzidé

Fr.: masse réduite   

The "effective" → inertial mass appearing in the → two-body problem of → Newtonian mechanics. The reduced mass is a quantity which allows the two-body problem to be solved as if it were a one-body problem. For the masses m1 and m2, it is given by the ratio μ = m1m2 / (m1 + m2). The value of μ is generally smaller than m1 and m2. The larger the difference between the two masses, the closer μ will be to the smaller mass. If the particles are of equal mass, μ is half the mass of either.

reduce; → mass.

reduced Planck constant
  پایای ِ پلانک ِ باز‌هازیده   
pâyâ-ye Planck-e bâzhâzidé

Fr.: constante de Planck réduite   

The → Planck constant divided by 2π and denoted ħ, pronounced h-bar. Also called the → Dirac constant.

Reduced, p.p. of → reduce; → Planck's constant.

reduced Planck's constant
  پایای ِ پلانک ِ باز‌هازیده   
pâyâ-ye Planck-e bâzhâzidé

Fr.: constante de Planck réduite   

reduced Planck constant.

reduced Planck constant.

reducing agent
  کنشگر ِ بازهازنده   
konešgar-e bâzhâzandé

Fr.: réducteur   

A substance which removes → oxygen from, or adds → hydrogen, to another substance. In the more general sense, one which loses electrons. Also called → reductant.

reduce; → -ing; → agent.

<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu coa coe coh col col col com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos Cou cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ Eri est Euc eva evo exc exc exh Exo exp exp ext ext f(R fac fam fat fee Fer Fib fig fin fir fix fle flu foc for for for fra fre Fre fri fun fuz Gal gal gal Gam gau Gay gen Geo geo geo geo gim glo gov gra gra gra gra gre gro Gun hab hal han Har haz hea hel hel Hen Her het Hig hil hol Hoo hor hou Hub hum hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind Ind inf inf inf inf inn ins ins int int int int int int int int inv ion ion Irr iso iso iso jan jit Jul jus Kel ker kin kni La lam lan Lap las lat Lay Led Len let lif lig lin lin lin liq Lit loc log lon lou low lum lun Lym M d Mag mag mag mag mag mag maj man mar mas mas mat mea mea mec mem mer Mes met met mho mic Mie Mil min mis MKS MOd mol Mon moo mot mul mul myo nak Nas nat neb neg neu neu New New nit noi non non nor nor nuc nuc nul nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi pai Pan par par Par par pas Pav Pel per per per per Per per pha phi pho pho pho phy Pip Pla pla PLA pla ple plu pol pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul pur qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea rea rec rec red red ref ref reg rel rel rel rep res res res res ret RHB rid rig ris roc Ros rot rub Rut Sag sam sat sca sca Sch sci Sea sec sec see sel sem sen set Sha sha shi shu sid sil sim sin SIS ski Slo smo Soc sol sol sol sol son sou spa spa spe spe spe sph spi spi Spo squ sta sta sta sta Ste ste ste sto str str str sub sub suc sun sup sup sup sup sur Swa syn syn tab tar tel tem ter tes the the the the Tho thr tid tim Tit top tot tra tra TRA tra tre tri tri tru Tun Tus tym Typ ult unb und uni uni uns upp Urs vac van var Vei Ven ver vic Vir vir vis vol W 4 war wat wav wea wed wet wid win WN2 Wol wri xen yok zen zin > >>