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 p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit 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 con Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg hyp ice ide ima Ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad ran rar ray rea rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr 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 tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>

Number of Results: 13048 Search : far
Gauss's lemma
  نهک ِ گاؤس   
nehak-e Gauss

Fr.: lemme de Gauss   

If a → polynomial with → integer coefficients can be → factorized into polynomials with → rational number coefficients, it can be factorized using only integers.

Gaussian; → lemma.

Gauss's theorem
  فربین ِ گاؤس   
farbin-e Gauss

Fr.: théorème de Gauss   

The total normal induction over any closed surface drawn in an electric field is equal to 4π times the total charge of electricity inside the closed surface. Gauss's theorem applies also to other vector fields such as magnetic, gravitational, and fluid velocity fields. The theorem can more generally be stated as: the total flux of a vector field through a closed surface is equal to the volume → integral of the vector taken over the enclosed volume. Also known as → divergence theorem, Ostrogradsky's theorem, and Gauss-Ostrogradsky theorem.

gauss; → theorem.

Gaussian
  گاؤسی   
Gaussi (#)

Fr.: gaussien   

Of or relating to Carl Friedrich Gauss or his mathematical theories of magnetism, electricity, astronomy, or probability. → Gaussian distribution; → Gaussian profile.

gauss.

Gaussian distribution
  واباژش ِ گاؤسی   
vâbâžeš-e Gaussi (#)

Fr.: distribution gaussienne   

A theoretical frequency distribution for a set of variable data, usually represented by a bell-shaped curve with a mean at the center of the curve and tail widths proportional to the standard deviation of the data about the mean.

Gaussian; → distribution.

Gaussian elimination
  اسانش ِ گاؤسی   
osâneš-e Gaussi

Fr.: élimination de Gauss   

A method of solving a matrix equation of the form A x = b, where A is a matrix and x and b are vectors. The process consists of two steps, first reducing the elements below the diagonal to 0 and second, back substituting to find the solutions.

Gaussian; → elimination.

Gaussian function
  کریای ِ گاؤس   
karyâ-ye Gauss

Fr.: fonction de Gauss   

The function e-x2, whose integral in the interval -∞ to +∞ gives the → square root of the → number pi: ∫e-x2dx = √π. It is the function that describes the → normal distribution.

Gaussian; → function.

Gaussian gravitational constant
  پایای ِ گرانشی ِ گاؤس   
pâyâ-ye gerâneši-ye Gauss

Fr.: constante gravitationnelle de Gauss   

The constant, denoted k, defining the astronomical system of units of length (→ astronomical unit), mass (→ solar mass), and time (→ day), by means of → Kepler's third law. The dimensions of k2 are those of Newton's constant of gravitation: L 3M -1T -2. Its value is: k = 0.01720209895.

Gaussian; → gravitational; → constant.

Gaussian integer
  درسته‌ی ِ گاؤس   
doroste-ye Gauss

Fr.: entier de Gauss   

A → complex number whose → real and → imaginary parts are both integers.

Gaussian; → integer.

Gaussian profile
  فراپال ِ گاؤسی   
farâpâl-e Gaussi

Fr.: profile gaussien   

The shape of a curve representing a normal distribution.

Gaussian; → profile.

Gaussianity
  گاؤسیگی   
Gaussigi

Fr.: gaussienité   

Math.: The condition of having → Gaussian distribution. The extent to which something is Gaussian.

Gaussian + → -ity.

Gay-Lussac's law
  قانون ِ گی-لوساک   
qânun-e Gay-Lussac (#)

Fr.: loi de Gay-Lussac   

1) Law of combining volumes. The volumes of gases used and produced in a chemical reaction, are in the ratio of small whole numbers when measured at constant temperature and pressure.
2) For a gas held at constant volume, there is a direct correlation between temperature and pressure: P1/T1 = P2/T2. Gay-Lussac's law, → Boyle-Mariotte law, and → Charles' law were later unified into the → ideal gas law.

Named after Joseph Louis Gay-Lussac (1778-1850), a French chemist and physicist; → law.

GCN: The Gamma-ray Coordinates Network
  توربست ِ هماراهای ِ پرتوهای ِ گاما   
turbast-e hamârâhâ-ye partowhâ-ye gâmâ

Fr.: Le réseau des coordonnées des rayons gamma   

A follow-up community network concerned with → gamma-ray burst (GRB)s. It deals with: 1) locations of GRBs and other → transients detected by spacecraft (most in real-time while the GRB is still bursting), and 2) reports of follow-up observations (the Circulars) made by ground-based and space-based optical, radio, X-ray, TeV, and other observers. The GCN Circulars allow the GRB follow-up community to make optimum use of its limited resources (labor and telescope time) by communicating what has already been done or will soon be done.

gamma ray; → coordinate; → network.

GD 165B
     
GD 165B

Fr.: GD 165B   

The prototype of the → L dwarf class. It has a spectral type of L4 V. This object was discovered by Becklin & Zuckerman (1988, Nature 336, 656) as the red companion to a → white dwarf (DA4) lying 104 → light-years away. Its true nature was however recognized several years later (Kirkpatrick et al. 1993, ApJ 406, 701). It has an → effective temperature of 1900 K and a luminosity about 10-4 times that of the Sun (→ solar luminosity).

GD, referring to Giclas Dwarf, a catalog of white dwarf stars compiled at the Lowell Observatory (Giclas et al. 1980, LowOB 8, 157).

gegenschein
  پادفروغ   
pâdforuq

Fr.: gegenschein, lueur anti-solaire   

A faint glow of light in the night sky seen exactly opposite the Sun. The gegenschein is sunlight back-scattered off millimeter-sized dust particles along the ecliptic. In comparison with zodiacal light (forward-scattered sunlight), which is triangular in shape and found near the horizon, the gegenschein is roughly circular. Same as counterglow.

Gegenschein, from Ger. gegen "counter, opposed to" (O.H.G. gegin, gagan, M.Du. jeghen, E. against, again) + Schein "glow, shine" (M.H.G. schinen, O.H.G. skinan, P.Gmc. *skinanan; E. shine; cf. Mod.Pers. sâyé "shadow;" Mid.Pers. sâyak "shadow;" Av. a-saya- "throwing no shadow;" Skt. chāya- "shadow;" Gk. skia "shade;" Rus. sijat' "to shine;" PIE base *skai- "bright").

Pâdfrouq "counterglow," from pâd- "agaist, contrary to" (from Mid.Pers. pât-; O.Pers. paity "agaist, back, opposite to, toward, face to face, in front of;" Av. paiti; cf. Skt. práti "toward, against, again, back, in return, opposite;" Pali pati-; Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti) + foruq "light, brightness" (related to rôšan "light; bright, luminous;" ruz "day," afruxtan "to light, kindle;" Mid.Pers. payrog "light, brightness," rošn light; bright," rôc "day;" O.Pers. raucah-; Av. raocana- "bright, shining, radiant," raocah- "light, luminous; daylight;" cf. Skt. rocaná- "bright, shining, roka- "brightness, light;" Gk. leukos "white, clear;" L. lux "light" (also lumen, luna; E. light, Ger. Licht, and Fr. lumière; PIE base *leuk- "light, brightness").

Geiger counter
  شمارگر ِ گایگر   
šomârgar-e Geiger (#)

Fr.: compteur Geiger   

A device for detecting ionizing radiations, whether corpuscular (α-, β-particles), or electromagnetic (X- and gamma-rays). It consists essentially of a fine wire anode (e.g., tungsten) surrounded by a coaxial cylindrical metal cathode, mounted in a glass envelope containing gas at low pressure. A large potential difference (800 to 2000 volts) is maintained between the anode and the cathode. The ionizing particle can enter through a thin glass or mica window. The particle produces ionization of gas molecules. The ions are accelerated by the electric field and produce more ions by collisions, causing the ionization current to build up rapidly. The current, however, decays quickly since the circuit has a small time constant. There is therefore a momentary potential surge which may be amplified and made to actuate a relay to advance a mechanical counter, or to produce a click in a loudspeaker. Same as Geiger-Mulle counter.

Named after Hans Geiger (1882-1945), the German physicist, who invented the instrument. He is also known for his work on atomic theory and cosmic rays; → counter.

geld
  اختن   
axtan (#)

Fr.: hongrer, castrer, châtrer   

To castrate (an animal, especially a horse).

M.E. gelden, from O.Norse gelda, ultimately from PIE *ghel- "to cut."

Axtan, variant of âxtan, âhixtan, âhiz- "to draw out; castrate, geld," → object.

gelding
  اخته   
axté (#)

Fr.: hongre, castré, castration   

A castrated male animal, especially a horse.

geld; → -ing.

Geminga
  گمینگا   
Geminga

Fr.: Geminga   

A bright → gamma-ray source discovered in 1973 in the constellation → Gemini with instruments aboard NASA's first γ-ray satellite SAS-2. It was known only as a γ-ray source until it was detected in X-rays by the Einstein Observatory and associated with an optical counterpart of apparent magnitude 25. Because its luminosity outside of the γ-ray region is extremely low, the nature of this object remained a mystery until the discovery of pulsed emission, by the → ROSAT satellite in 1992, showed that it is a → pulsar. The pulsar period (~237 milliseconds) and its → period derivative (~1.1 × 10-14 s s-1) correspond to a → spin-down age of ~340,000 years. Also called PSR J0633+1746 (see Bignami & Caraveo 1996, ARA&A 34, 331 for a review).

An abbreviation for the Gemini gamma ray source. More amusingly, Geminga has been related to the Italian dialectal ghè minga spoken by the involved astronomers. This, in Milanese, means "it's not there," referring to the fact that the source could not be detected in the radio frequencies, one of the ongoing enigmas.

Gemini
  دوپیکر   
dopeykar (#)

Fr.: Gémeaux   

The Twins. A prominent constellation of the northern hemisphere and the third (and northernmost) of the → Zodiac. It lies south and east of → Auriga, west of → Cancer, and north and east of → Orion, at 7h right ascension and +22° declination. Its brightest stars are → Castor and → Pollux. Abbreviation: Gem; genitive: Geminorum.

Gemini, from M.E., from L. gemini, plural of geminus "twin; double;" cf. Av. yəma- "twin;" Skt. yamá-, yamala- "twin, paired;" Persian dialects Kermâni jomoli "twin," Qâyeni jamal "twin," Tabari da-cembali "twin;" PIE base *iem- "to hold."

Dopeykar, from do "two" (Mid.Pers. do, Av. dva-; Skt. dvi-; Gk. duo; L. duo ( Fr. deux); E. two; Ger. zwei) + peykar "figure, form, body" (from Mid.Pers. pahikar "picture, image;" from O.Pers. patikara- "picture, (sculpted) likeness," from patiy "against" (Av. paiti; Skt. prati; Gk. poti/proti) + kara- "doer, maker," from kar- "to do, make, build;" Av. kar-; Skr. kr-; cf. Skt. pratikrti- "an image, likeness, model; counterpart").

Geminids
  دوپیکریان   
dopeykariyân (#)

Fr.: Géminides   

A → meteor shower that occurs in the first half of December, with its → radiant in the → constellation → Gemini. Geminids are pieces of debris from the extinct comet → 3200 Phaethon. The shower appears when Earth runs into a stream of the debris every year in mid-December, causing → meteors to fly from that constellation.

Gemini + → -ids.

<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit 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 con Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg hyp ice ide ima Ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad ran rar ray rea rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr 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 tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>