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
celestial object
  بر‌آخت ِ آسمانی   
barâxt-e âsmâni

Fr.: objet céleste   

astronomical object.

celestial; → object.

celestial pole
  قطب ِ آسمان   
qotb-e âsmân (#)

Fr.: pole céleste   

The point of the sky, north or south, where the projection of the Earth's axis of rotation intersects the → celestial sphere. They are at 90° relative to the → celestial equator. Because of → precession, the celestial poles describe a circle around the ecliptic's poles every 25,800 years.

celestial; → pole.

celestial sphere
  سپهر ِ آسمانی، کره‌ی ِ ~   
sepehr-e âsmân (#), kore-ye ~ (#)

Fr.: sphère céleste   

An imaginary sphere, of large but indefinite dimension, used as a basis to define the position coordinates of celestial bodies. The center can be the Earth, the observer, or any other point which plays the role of origin for a given system of coordinates. Seen from the Earth, the celestial sphere rotates around the → celestial axis every 23h 56m 04s (the → sidereal day), as a result of the Earth's rotation. Two important circles on the celestial sphere are the → celestial equator and the → ecliptic. The angle between them, about 23.40 degrees, is known as the → obliquity of the ecliptic. The celestial equator and the ecliptic intersect at two points, → vernal equinox and → autumnal equinox. The positions of the → celestial poles and therefore that of the → celestial equator move gradually on the celestial sphere, due to → precession.

celestial; → sphere.

cell
  ۱، ۲) یاخته؛ ۳) پیل، باتری   
1, 2) yâxté (#); 3) pil, bâtri (#)

Fr.: 1, 2) cellule; 3) élément, pile   

1) General: A small compartment or bounded area forming part of a whole.
2) Fluid mechanics: A body of fluid (air, liquid, or → plasma) in which the process of → convection proceeds.
3) Electricity: A device for producing electric current by chemical action.

From L. cella "small room, hut," related to L. celare "to hide, conceal," from PIE base *kel- "conceal" (cf. Skt. cala "hut, house," Gk. kalia "hut, nest," kalyptein "to cover").

Yâxté "small room, closet," etymology unknown.

Celsius scale
  مرپل ِ سلسیوس   
marpel-e Celsiu

Fr.: échelle de Celsius   

The official name of the centigrade temperature scale with the → ice point as 0° and the → boiling point of water as 100°. The Celsius scale uses a degree (the unit of temperature) which has the same magnitude as the degree on the → Kelvin scale: TC = TK - 273.15. See also → Fahrenheit scale, → Rankine scale, → Reaumur scale.

In honor of Anders Celsius (1701-1744), Swedish astronomer, originator of the first centigrade temperature scale. However, in his original scale Celsius had 100° for the ice point and 0° for the steam point; → scale.

Centaur asteroid
  سیارک ِ کنتاؤر   
sayyârak-e Kentâwr (#)

Fr.: astéroïde Centaure   

An → asteroid whose orbit around the Sun lies typically between the orbits of → Jupiter and → Neptune Neptune (5 to 30 → astronomical units). The first Centaur, called → Chiron, was discovered in 1977, but since then more than 100 roughly similar objects have been found. Three centaurs, Chiron, 60558 Echeclus, and 166P/NEAT 2001 T4, have been found to display → cometary  → comas. Chiron and 60558 Echeclus are now classified as both asteroids and → comets. Most of the Centaur asteroids are probably dormant comets from the → Kuiper belt which have been pulled in by the gravity of → outer planets.

Centaurus; → asteroid.

Centaurus
  کنتاؤروس   
Kentâwros (#)

Fr.: Centaure   

The Centaur. A → constellation in the southern hemisphere covering an extensive area of about 1060 square degrees from R.A. 11 h to 15 h and Dec. -30° to -64°. Abbreviation: Cen, genitive form: Centauri. Centaurus is the ninth largest constellation in the sky, but it does not contain any → Messier objects. The brightest star in constellation is → Alpha Centauri which is also the third brightest star in the sky. Beta Centauri, the second brightest star in Centaurus, also called → Hadar, is the eleventh brightest star in night sky. Among other bright stars of the constellation are: Menkent (θ Cen), γ Cen, ε Cen, and η Cen. There are three → meteor showers associated with the constellation: the Alpha Centaurids, the Omicron Centaurids, and the Theta Centaurids. The constellation contains several extragalactic objects, among which: Centaurus A (NGC 5128), Omega Centauri, and NGC 5139.

L. centaurus, from Gk. kentauros, cf. Av. gandarəwa- "a mythical monster killed by Kərəsâspa," Skt. gandharva- "name of mythical beings related with Soma." In Gk. mythology, centaurs were half-man half-horse creatures living on Mount Pelion in Thessaly, northern Greece. They were followers of the wine god Dionysus and well known for drunkenness and carrying off helpless young maidens.

Kentâwros, from Gk. "Kentauros." Arabicized Qenturis (قنطورس).

Centaurus A
  کنتاؤروس A   
Kentâwros A

Fr.: Centaurus A   

The closest (3.8 ± 0.1 Mpc) → radio galaxy with a physical age of about 560 Myr, associated with the massive → elliptical galaxy NGC 5128. The nucleus harbours a → supermassive black hole, with a mass (5.5 ± 3.0) × 107 Msol derived from stellar → kinematics. A prominent → dust lane, with → starburst, crosses the central parts. Centaurus A shows a twin → jet in → radio and → X-ray bands, symmetrical on parsec scales but with evident asymmetry on kpc scales. The main (i.e. northern) jet which is markedly brighter than the counterjet, is seen at a viewing angle of approximately 50°. From photoionization models for such a viewing angle, the → Lorentz factor of the jet is derived to be ≤ 5. A large number of radio and X-ray → knots is discernible in the jet on kpc scales with the radio knots of larger proper motions showing comparatively little X-ray emission (see S. Wykes et al. 2015, MNRAS 447, 1005, and references therein).

Situated in the → Centaurus constellation.

Centaurus supercluster
  ابرخوشه‌ی ِ کنتاؤروس   
abarxuše-ye Kentawros

Fr.: superamas du Centaur   

The nearest large → supercluster. It is dominated by the → galaxy cluster A3526 (→ Abell catalog). The Centaurus supercluster is a long structure that stretches away from us. The most distant of the clusters, A3581, is about 300 million → light-years away.

Centaurus; → cluster.

center
  مرکز، کیان   
1) markaz (#), kayân (#); 2) markazidan

Fr.: 1) centre; 2) centrer   

1) The point that is equidistant from all the points on a circle or sphere.
2a) To place in or on a center.
2b) Telescope: To move a telescope in order to place the object of interest on the center of the field. → center of attraction, → center of gravity, → center of inertia, → center of mass, → center wavelength, → anticenter, → apocenter, → barycenter, → optical center, → pericenter.

M.E. centre, from O.Fr. centre, from L. centrum "center," originally fixed point of the two points of a compass, from Gk. kentron "sharp point, goad," from kentein "stitch," from PIE *kent- "to prick."

Markaz "center," from Ar.; kayân, Mod.Pers. "the point made by the compasses, that is the center of a circle" [Dehxodâ]; markazidan, infinitive from markaz, → center, + -idan infinitive suffix.

center of attraction
  مرکز ِ درکشش   
markaz-e darkašeš

Fr.: centre d'attraction   

A point toward which a force on a body is always directed.

center; → attraction.

center of gravity
  گرانیگاه   
gerânigâh (#)

Fr.: centre de gravité   

A fixed point in a body through which the resultant force of gravitational attraction acts. Same as → center of mass, → center of inertia, → centroid.

center; → gravity.

Gerânigâh, from gerânigravity + -gâh "place."

center of inertia
  گرانیگاه   
gerânigâh (#)

Fr.: centre d'inertie   

Same as → center of gravity, → center of mass, → centroid.

center; → inertia.

center of mass
  گرانیگاه   
gerânigâh (#)

Fr.: centre de masse   

Same as → center of gravity, → center of inertia, → centroid, and → barycenter.

center; → mass.

center wavelength
  موج-طول ِ مرکز   
mowjtul-e markaz

Fr.: longueur d'onde centrale   

Center of a filter passband measured at 50% of peak transmittance.

center; → wavelength.

centi-
  سانتی-   
sânti- (#)

Fr.: centi-   

Prefix denoting one-hundredth of, in metric units; e.g. centimeter, 0.01 of meter.

Fr., from L. centi,- "hundred," from centum "hundred," Gk. hekaton, Av. satem-, Mod.Pers. sad, Skt. satam-, P.Gmc. *hunda- "hundred," Goth. hund, O.H.G. hunt, O.Ir. cet, Bret. kant, PIE *kmtom "hundred."

Sânti-, from Fr., → above paragraph.

centimeter (cm)
  سانتی‌متر   
sântimetr (#)

Fr.: centimètre   

A unit of length in the → metric system, equal to one-hundredth of a meter, which is the current unit of length in the → International System of Units (SI).

centi-; → meter.

Central cluster
  خوشه‌ی ِ مرکزی   
xuše-ye markazi

Fr.: amas central   

One of the three obscured → Galactic center clusters, which contains the supermassive black hole → Sgr A*. The first stars observed in the Central cluster were evolved → massive stars showing strong He I emission lines (2.058 microns) in the near infrared K band. Subsequently more than 80 massive stars were detected including various types of → Wolf-Rayet stars, as well as → O-type and → B-type → supergiants and → dwarfs (see, e.g. Martins et al. 2007, A&A 468, 233).

central; → cluster.

central eclipse
  گرفت ِ مرکزی   
gereft-e markazi

Fr.: éclipse centrale   

An eclipse during which the axis of the lunar shadow cone intersects the Earth's surface (in the case of solar eclipses) or the axis of the terrestrial shadow cone intersects the Moon's surface (in the case of lunar eclipses). The total and annular solar eclipses are usually central. They can also be not central; then, they are visible only from places situated at high latitudes (M.S.: SDE).

central force
  نیروی ِ مرکزی   
niru-ye markazi

Fr.: force centrale   

A → force that is always directed toward a fixed point and whose → magnitude depends only on the distance from that point. Mathematically, F is a central force if and only if: F = f(r)r1 = f(r)r/r, where r1 = r/r is a unit → vector in the direction of r. If f(r) < 0 the force is said to be → attractive toward the source. If f(r) > 0 the force is said to be → repulsive from the source. In other words, a central force is one whose → potential, V(r), depends only on the → distance from the source. → Gravitational force and → electrostatic force are central, with V(r)∝ 1/r.

central; → force.

<< < -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 > >>