An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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<< < -es -iv -ti 21- a p abe abs abs acc acc acc act act ada adi ads aes Age Alb Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app app arb are ari art ass ast ast ast Atl ato ato Aug aut Avo azi bac bal ban bar bas bea bel Bet bia Big bin bio bir bla bla blo blu Boh Bon bot Bow bre Bri bro but cal cal Can Cap car cas cat cau cel cen cen cha cha cha che Chi chr cir cir civ Cla clo clu CNO coa coe coi 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 cro Cru cub cur cyc cyl dar dat Daw de- Deb dec dec def 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 erg est Euc eva evo exa exc exe exo exp exp ext ext f m fac fal fas fee Fer fib fie fin Fir fix fle flu foc for for For fou Fra fre Fri ful fuz Gal Gal gal Gam gas Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro gul H-b hal Ham har Hay hea hel hel hem her het Hig hik hol hom hor hot Hub hum hyb hyd hyd hyp hyp ide ign ima imp imp imp inc ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos jun K-T Kep key kin Kol lad Lam lan lar las lat lea leg len lev lig lik lin lin lin Lis lob loc log loo low lum lun lun Lym Mac Mag mag mag mag mag Mag mak map Mar mas mat mat mea mea med mem mer MES met met MHD mic mid mil min mis mix mod mol mom Moo mos Mu mul mus nab nar nat neb neg nes neu New New nig nod non non non Nor noz nuc nul num OB obl obs Occ oct off Ohm on- ope Opp opt opt orb orb org Ori ort osm out ove ozo pal pap par par par pas pat pec pen per per per per per pH pha pho pho pho phy pie pla Pla Pla pla pla Plo poi pol pol pol pol por pos pot pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sag sam sat sca Sch Sch sco sec sec sec seg sel sem sen set sha Sha sho SI sid sil sim sin sis sky slo sna Soc sol sol sol Sol Som sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn sys tan Tay Tem ten ter The the the the thi thr tic tid tim Tol tor tot tra tra tra tra Tri tri tro tru tur two Typ UHE ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol WZ Yag yot zen zir > >>

Number of Results: 13033 Search : far
Chinese calendar
  گاهشمار ِ چینی   
gâhšomâr-e Cini

Fr.: calendrier chimois   

A → lunisolar calendar (Chinese: yīnyáng li), which is now mainly used for determining cultural festivals. It is based on astronomical observations of the Sun's annual apparent motion (→ ecliptic) and → lunar phases. The calendar starts at Chinese New Year and consists of 12 or 13 → lunar months. The ecliptic is divided into 24 sections (jiéqi) of 15° each. In general, Chinese New Year falls on the day of the second new Moon after the → winter solstice on approximately December 22. Since 12 months are about 11 days shorter than the → tropical year, a → leap month is inserted to keep the calendar in tune with the seasons. An ordinary → lunar year has 353-355 days while a → leap year has 383-385 days. Therefore, the → solstices and → equinoxes move 11 (or 10 or 12) days later. Each 13-month leap year is about 19 days too long, so the solstices and equinoxes jump 19 (or 18 or 20) days earlier. Each year is assigned a name consisting of two components within a 60-year cycle. The first component is a celestial stem. The second component is a terrestrial branch; it features the names of animals in a zodiac cycle consisting of 12 animals. Each of the two components is used sequentially. Therefore, the first year of the 60-year cycle becomes jia-zi, the second year is yi-chou, and so on. One starts from the beginning when the end of a component is reached. The 60th year is gui-hai. The current 60-year cycle started on 2 February 1984. The leap year must be inserted if there are 13 new moons from the start of the 11th month in the first year to the start of the 11th month in the second year. The beginnings of the Chinese calendar can be traced back to the 14th century BC. Legend has it that the Emperor Huang-di invented the calendar in 2637 BC. The calendar has been adopted by several southeast Asian cultures. The Chinese calendar has undergone several reforms, the last one in 1645. For more details, see, e.g., Helmer Aslaksen, The Mathematics of the Chinese calendar, e-paper.

Chinese adj. of China, from Pers. Cin [Chin], from Qin the first imperial dynasty of China (221 to 206 BC); → calendar.

chiral
  خیرال   
xirâl

Fr.: chiral   

The quality of an object that is not superimposable on its mirror image.

From Gk. cheir "hand;" from PIE *ghes- "hand."

Xirâl, loan from Gk., as above.

chirality
  خیرالی   
xirâli

Fr.: chiralité   

The geometric property of a rigid object that is → chiral.

chiral; → -ity.

Chiron
  خیرون   
Xeiron (#)

Fr.: Chiron   

An object, discovered in 1977, which was initially assumed to be an asteroid, but subsequent observations showed it to be a weak comet with a detectable coma. Its orbit, lying now between those of Saturn and Uranus, is unstable on time scales of a million years.

In Gk. mythology, Xειρων (Cheiron or Chiron) was the wisest of the Centaurs; he was not a drunkard like other Centaurs. Chiron was tutor to Jason and Heracles. He was the only immortal centaur.

chirp
  چیرپ   
cirp

Fr.: compression d'impulsion   

1) Telecommunications: A signal in which the wave frequency increases or decreases, linearly or exponentially, with time.
2) Astro: The theoretically predicted → gravitational wave arising from the interaction of two highly → compact objects. As the two objects spiral toward each other, due to orbital energy loss, the frequency and amplitude of the gravitational wave will increase continuously.

Chirp "a short, high-pitched sound, such as that made by certain birds or insects," from M.E. chirpen, of onomatopoeic origin.

Cirp loanword from E., as above.

Chladni pattern
  الگوی ِ کلادنی   
olgu-ye Chladni

Fr.: figure de Chladni   

A pattern formed by fine powder or salt placed on a vibrating surface. The figures display the positions of → nodes and → antinodes.

Named after Ernst Chladni (1756-1827), German physicist; → figure.

chlorate
  کلرات   
klorât (#)

Fr.: chlorate   

1) A negative ion, ClO3- derived from chloric acid.
2) Any salt of chloric acid.

From chlor-, → chlorine, + → -ate.

chloric acid
  اسید کلریک   
asid klorik (#)

Fr.: acide chlorique   

A colorless, strong acid HClO3, formed by the action of dilute sulfuric acid on barium chlorate.

From chlor-, → chlorine, + → -ic; → acid.

chlorine
  کلور   
klor (#)

Fr.: chlore   

A gaseous → chemical element of the halogen group, which is greenish yellow and poisonous; symbol Cl. → Atomic number 17; → atomic weight 35.453; → melting point -100.98°C; → boiling point -34.6°C. Chlorine is about two and one-half times as dense as air. It is used for water purification, in the making of bleaching powder. Its compounds occur as common → salt (sodium chloride), NaCl, in sea water and as rock salt. Chlorine is the first poison gas to be used in warfare (by German army, the Second Battle of Ypres, 1915). It has several → radioactive isotopes, in particular 36Cl with a half-life of 3 × 105 years. Chlorine was discovered by the Swedish pharmacist and chemist Carl-Wilhelm Scheele (1742-1786) in 1774. In 1810, the English chemist Humphry Davy (1778-1829) proved it was an element and gave it the name chlorine.

From Gk. chloros "light green, greenish yellow;" cognate with Pers. zard "yellow," zarr "gold;" E. → gold, → yellow.

chondrite
  کوندریت   
kondrit

Fr.: chondrite   

The most common type of → meteorites containing → chondrules. These → stony meteorites make up about 86% of all meteorites. An important feature of the chondrites is that, with the exception of a few highly → volatile elements, they have the same composition as the Sun.

Chondrite, from chondr-, from chondros "grain", + suffix → -ite.

chondrule
  کوندرول   
kondrul

Fr.: chondrule   

Millimeter-sized grains of → silicate sometimes found in large numbers in → chondrite meteorites. They are essentially glassy beads made by a violent but brief heating event that caused dust grains to form melt droplets. However, the cause of the heating remains unknown.

From Gk. chondr-, from chondros "grain," + diminutive suffix → -ule.

chough
  کلجیک   
kalajik

Fr.: crave à bec rouge   

A member of the → crow family with a red beak and legs.

M.E. choghe; akin to O.E. ceo, Du. kauw, Dan. kaa.

Kalajik, from Daštak Baxtiyâri dialect, related to kal, kalâq, → crow.

Christoffel symbol
  نماد ِ کریستوفل   
namâd-e Christoffel (#)

Fr.: symbole de Christoffel   

A abbreviated notation for various functions associated with quadratic differential forms. Each Christoffel symbol is essentially a triplet of three indices, i, j and k, where each index can assume values from 1 to 2 for the case of two variables, or from 1 to n in the case of a quadratic form in n variables. Christoffel symbols appear in many calculations in geometry where non-Cartesian coordinates are used. These symbols are fundamental in the study of tensor analysis.

Named after Elwin Bruno Christoffel (1829-1900), a German mathematician; → symbol.

chromatic
  رنگی، فامی   
rangi, fâmi

Fr.: chromatique   

Of or relating to color or color phenomena or sensations.

From L. chromaticus, from Gk. khromatikos "relating to color," from khroma, khromat- "color" + → -ic.

From rang, fâm, → chromo-, + -i adj. suffix.

chromatic aberration
  بیراهش ِ رنگی   
birâheš-e rangi

Fr.: aberration chromatique   

A defect in a lens that causes it to concentrate the various colors in a beam of light at various point, thus producing color fringes.

chromatic; → aberration.

chromium
  کروم   
krom (#)

Fr.: chrome   

A silver-gray, lustrous, brittle, hard metallic → chemical element that is resistant to tarnish and corrosion; symbol Cr. → Atomic number 24; → atomic weight 51.996; → melting point about 1,857°C; → boiling point about 2,672°C; → specific gravity about 7.2 at 20°C. Chromium is used in the hardening of steel alloys and the production of stainless steels. It is extracted by reducing the oxide with → aluminium. Its → radioactive isotope 51Cr has a half-life of 27.8 days. It was discovered in 1797 by the French chemist and pharmacist Nicolas-Louis Vauquelin (1763-1829).

From the Gk. chroma "color," from the many colored compounds of this element, + -ium a suffix used in the name of several chemical elements.

chromo-
  رنگ-، فام-   
rang-, fâm-

Fr.: chromo-   

A prefix indicating "color, colored." Before a vowel: chrom-.

Combining form from Gk. chroma, khroma "color."

Rang, → color; fâm "color," probably related to bâm "light; morning light; splendor" (bâmdâd "morning,; splendor, light"); Mid.Pers. bâm "brillance, glory, splendor," bâmig "brilliant, glorious;" Av. bā- "to shine, appear, seem," (with ā-) auuā- "to have the appearance of, be like," (with fra-) frauuā- "to shine," (with ni-) -niuuā- "to radiate downward," (with ui-) viuuā- "to shine forth;" cf. Gk. phaos, phos "light," phainein "to show, to bring to light;" Skt. bhā- "to shine," bhati "shines, glitters," O.Ir. ban "white, light, ray of light."

chromodynamics
  رنگ توانیک   
rangtavânik

Fr.: chromodynamique   

A → quantum field theory of the → interaction of → quarks possessing a distinctive property called → color, in which the quarks exchange → gluons in a manner that is analogous to the interaction of → charged particles in → electrodynamics.

chromo-; → dynamics.

chromosphere
  فام‌سپهر، رنگین‌سپهر   
fâmsepehr (#), ranginsepehr (#)

Fr.: chromosphère   

A region of the stellar atmosphere situated above its → photosphere. The Sun's chromosphere extends from the about 500 km above the photosphere basis, up to 9,000 km, where it meets the → corona. For a plane-parallel model, the chromosphere is more or less continuous throughout the first 1,500 km, but breaks into indented spicules beyond that height. The chromosphere temperature grows from 4,400 K at 500 km to almost 6,000 K at 1,000-2,000 km. A rapid growth of coronal temperatures is registered at heights of about 2,500 km (the transition region), the exact height depending on the local magnetic field intensity. Actually, the chromosphere is made of rising and, often, falling jets called → spicules, which go up to 15,000 km. In the uppermost part of the chromosphere the density is the millionth part of its density at the base. Immediately before or after a solar → total eclipse, the chromosphere becomes visible either as a crescent or as a red → diamond ring, due to → H-alpha emission, from which it also gets its name. Moreover, the chromosphere can be seen in → H and K lines of calcium during eclipses, and in ultraviolet emission lines from space. The presence of the chromosphere around cold → dwarf stars is deduced from similar emissions (M.S.: SDE).

chromo- "color," because of the reddish-pink color of the chromosphere which is seen around the Sun during a total eclipse and is due to the dominance of the → H-alpha line; → sphere.

chronograph
  گاه‌نگار   
gâhnegâr

Fr.: chronographe   

A very accurate instrument that measures, indicates, or graphically records time intervals such as the duration of an event.

Chronograph, from Gk. khronos "time" + → -graph.

Gâhnegâr, from gâh "time" + negâr, → -graph.

<< < -es -iv -ti 21- a p abe abs abs acc acc acc act act ada adi ads aes Age Alb Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app app arb are ari art ass ast ast ast Atl ato ato Aug aut Avo azi bac bal ban bar bas bea bel Bet bia Big bin bio bir bla bla blo blu Boh Bon bot Bow bre Bri bro but cal cal Can Cap car cas cat cau cel cen cen cha cha cha che Chi chr cir cir civ Cla clo clu CNO coa coe coi 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 cro Cru cub cur cyc cyl dar dat Daw de- Deb dec dec def 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 erg est Euc eva evo exa exc exe exo exp exp ext ext f m fac fal fas fee Fer fib fie fin Fir fix fle flu foc for for For fou Fra fre Fri ful fuz Gal Gal gal Gam gas Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro gul H-b hal Ham har Hay hea hel hel hem her het Hig hik hol hom hor hot Hub hum hyb hyd hyd hyp hyp ide ign ima imp imp imp inc ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos jun K-T Kep key kin Kol lad Lam lan lar las lat lea leg len lev lig lik lin lin lin Lis lob loc log loo low lum lun lun Lym Mac Mag mag mag mag mag Mag mak map Mar mas mat mat mea mea med mem mer MES met met MHD mic mid mil min mis mix mod mol mom Moo mos Mu mul mus nab nar nat neb neg nes neu New New nig nod non non non Nor noz nuc nul num OB obl obs Occ oct off Ohm on- ope Opp opt opt orb orb org Ori ort osm out ove ozo pal pap par par par pas pat pec pen per per per per per pH pha pho pho pho phy pie pla Pla Pla pla pla Plo poi pol pol pol pol por pos pot pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sag sam sat sca Sch Sch sco sec sec sec seg sel sem sen set sha Sha sho SI sid sil sim sin sis sky slo sna Soc sol sol sol Sol Som sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn sys tan Tay Tem ten ter The the the the thi thr tic tid tim Tol tor tot tra tra tra tra Tri tri tro tru tur two Typ UHE ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol WZ Yag yot zen zir > >>