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 awa azi bac bal Bar Bar Bay bea Bep Bet BIC bij bin bio bir bla bla blu blu bol Boo bou Bq bre bri bub B[e cal cal can car car Cas cat cau cel cen Cer cha cha cha che chi CI cir cir cla cle clo clu co- cob 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 coo cor cor cor cos cos cos cou cov cra cri cro cry cum cur cyc d'A dar dat DC dea dec dec dec def def deh Del den dep des det deu dia dif dif dif dim dip Dir dis dis dis dis dis div dom dos dou dri Dum dus dyn dyn ear eas ecl Edd eff Ein eje ele ele ele ele eli emb emi Enc ene ens eph epo equ equ eru eth Eul eve evo exc exc exi exo exp exp ext ext Fab fai Fan fea fem fer fie fil fir fir fla flo flu foc For for fos fra fre fre fro fun g m Gal gal gal gas gau gel gen geo geo geo gho gla gno gra gra gra gra Gre Gre gro gyr had hal har Har HD hea hel hel Her Her Hic hig hip hol hor hos hov Hub hun hyd hyd Hyd hyp IC ide ill ima imp imp inc inc ind ind inf inf inf inf inj ins ins int int int int int int int int inv inv ion iro Isl iso iso Jac jet jud jur kel Kep kil Kle 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 Mei Mer Mer met met Met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per pet pha Pho pho pho pho Pic Pis Pla pla pla pla Ple poa pol pol pol pol pop pos pos pow pra pre pre pre pri pri pri pro pro pro pro pro pro pro Pto pul puz 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 Rhe rid rig ris Roe Ros rot rub rut Sag sam sat sca sca Sch sci sea sec sec see sel sem sen ser Sgr sha shi sho sid sig sim sin Sir ske sli smo soc sol sol sol sol sol sou sou spa spe spe spe spe sph spi spl spu sta sta sta sta sta ste ste sti sto str Str sub sub sub sul sup sup sup sup sur sus sym syn sys Tam Tay tel ten Ter Tha the the the thi thr tib tid tim tok Tor tot tra tra tra tra Tri tri tro tru tur twi Typ ufo ult unc uni uni uni upl ura uti val var vec vel ver ver vil vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yea You zer zod > >>

Number of Results: 13009 Search : far
chemical potential
  توند ِ شیمیک   
tavand-e šimik

Fr.: potentiel chimique   

For a given component in a → gas mixture, the change in → Gibbs free energy (G) with respect to change in amount of the component (n), when pressure, temperature, and amounts of other components remain constant: ∂G/∂n. Components are in equilibrium if their chemical potentials are equal.

chemical; → potential.

chemical reaction
  واژیرش ِ شیمیایی، واکنش ِ ~   
vâžireš-e šimiyâyi, vâkoneš-e ~

Fr.: réaction chimique   

A → change or → transformation in which a → substance → decomposes, → combines with other → substances, or interchanges constituents with other substances.

chemical; → reaction.

chemical separation
  جدایی ِ شیمیایی   
jodâyi-ye šimiyâyi

Fr.: séparation chimique   

The physical processes that can cause certain elements to migrate in a → stellar atmosphere. These processes are thought to be important in creating the chemical peculiarities seen in → Am stars and → Ap stars.

chemical; → separation.

chemical species
  آرز ِ شیمییایی   
âraz-e šimiyâyi

Fr.: espèce chimiique   

A set of chemically → identical  → atomic or → molecular entities.

chemical; → species.

chemically peculiar star
  ستاره‌ی ِ شیمیکانه افد   
setâre-ye šimikâné afd

Fr.: étoile chimiquement particulière   

A → main sequence star of → spectral type A or B (→ A-type star, → B-type star) identified by the presence of anomalously strong or weak → absorption lines of certain elements in their spectra. CP stars have been divided into four main classes on the basis of their spectra: 1) non-magnetic metallic-lined (CP1, → Am star), magnetic (CP2, → Ap star), non-magnetic mercury-manganese (CP3, → HgMn star), and helium-weak (CP4, → He-weak star).
See also → Ap/Bp stars.

chemical; → -ly; → peculiar; → star.

chemiluminescence
  شیمی-فروزستی   
šimi-foruzesti

Fr.: chimiluminescence   

The production and emission of light via a → chemical reaction.

Chemi-, → chemo-; → luminescence.

chemisorption
  شیمی‌شمش   
šimi-šameš

Fr.: chimisorption   

A kind of → adsorption in which the forces involved are → valence forces of the same kind as those operating in the formation of → chemical compounds. Same as → chemical adsorption. See also → physisorption.

Chemi-, from → chemical; → sorption.

chemistry
  شیمی   
šimi (#)

Fr.: chimie   

The science of the composition, structure, properties, and reactions of chemical elements and compounds and their interactions with matter and energy.

Chemistry, from chemist, from Gk. chemia "alchemy" + -ry, from M.E. -rie, from O.Fr.

Šimi, from Fr. as above.

chemo-
  شیمی-   
šimi- (#)

Fr.: chimio-   

A combining form meaning "chemical, chemically induced, chemistry," used in the formation of compound terms like → chemosynthesis. Also chem- (before a vowel) and chemi- (before elements of L. origin).

Chemo- extracted from → chemical or → chemistry.

chemosynthesis
  شیمی‌هندایش   
šimihandâyeš

Fr.: chimiosynthèse   

In biochemistry, the ability to produce organic compounds using energy contained in inorganic molecules. Chemosynthesis is similar to → photosynthesis. Instead of using light as an energy source to make food, energy or compounds from chemical reactions is used. Most chemosynthetic organisms are bacteria.

chemo-; → synthesis.

Cheops
  خءوپس   
Cheops

Fr.: Cheops   

The first mission, conducted by the → European Space Agency, dedicated to searching for → exoplanetary transits by performing ultra-high precision → photometry on bright stars already known to host planets. Launched on 18 December 2019, Cheops is a small spacecraft with a launch mass (including propellant) of approximately 280 kg. It has a single instrument: a high precision → photometer with a 300 mm effective aperture telescope and a single → charge-coupled device (CCD) → detector covering → visible to → near-infrared wavelengths. The mission's main science goals are to measure the bulk density of → super-Earths and Neptunes orbiting bright stars and provide suitable targets for future in-depth characterization studies of → exoplanets in these mass and size ranges.

CHEOPS, short for CHaracterising ExOPlanet Satellite.

Cherenkov radiation
  تابش ِ چرنکوف   
tâbeš-e Čerenkov (#)

rayonnement de Čerenkov   

Visible radiation emitted when → charged particles pass through a transparent medium faster than the speed of light in that medium.

Named after Pavel A. Čerenkov (1904-1990), Russian physicist, who discovered the phenomenon. He shared the Nobel prize 1958 in physics with Ilya Frank and Igor Tamm, who in 1937 gave the theoretical explanation for this radiation.

chi-square distribution
  واباژش ِ خی-دو   
vâbâžeš-e Xi-do

Fr.: loi du chi-deux   

A probability density function, denoted χ2, that gives the distribution of the sum of squares of k independent random variables, each being drawn from the normal distribution with zero mean and unit variance. The integer k is the number of degrees of freedom. The distribution has a positive skew; the skew is less with more degrees of freedom. As degrees of freedom increase, the chi-square distribution approaches a normal distribution. The most common application is chi-square tests for goodness of fit of an observed distribution to a theoretical one. If χ2 = 0 the agreement is perfect.

Chi Gk. letter of alphabet; → square; → distribution.

Vâbâžeš, → distribution; do, → two.

Chicxulub crater
  لاوک ِ چیکخولوب   
lâvak-e Cikxulub

Fr.: Cratère de Chicxulub   

A crater about 200 km in diameter on the northern coast of the Yucatan Peninsula, near the town of Chicxulub, Mexico. It is attributed to a 10 km wide → asteroid that hit the Earth about 65 million years ago (→ Chicxulub impactor). Ten years before the 1990 discovery of the Chicxulub crater, physicist Luis Alvarez and geologist Walter Alvarez proposed a theory to explain the formation of the crater. They noted increased concentrations of the element → iridium in 65-million-year-old clay. Iridium is rare on Earth, but it's more common in some objects from space, like → meteors and asteroids. According to the Alvarez theory, a massive asteroid had hit the Earth, blanketing the world in iridium. The collision caused fires, climate change and widespread extinctions, among which that of dinosaurs, who had lived for 180 million years.

Named after a twon in the Mexican state of Yucatan, which lies near the geographic center of the → crater.

Chicxulub impactor
  برخوردگر ِ چیکخولوب   
barxordgar-e Cikxulub

Fr.: impacteur de Chicxulub   

An object having an estimated mass between 1.0 × 1015 and 4.6 × 1017 kg, which struck the Earth at the → Cretaceous-Tertiary event about 65 million years ago. It was probably an → asteroid 10 km in diameter with a velocity of roughly 20 km per sec at an angle of just under 60°. The collision created the → Chicxulub crater. The event was responsible for eliminating approximately 70 percent of all species of animals at or very close to the boundary between the Cretaceous and Paleogene periods.

Chicxulub crater; → impactor.

child
  فرزند   
farzand (#)

Fr.: enfant   

1) A person between birth and puberty; a son or daughter; an offspring.
2) In → graph theory, the → vertex (node) below a given vertex connected by its → edge downward. In other words, in a rooted tree, a vertex v is a child of vertex w if v immediately succeeds w on the path from the root to v. Vertex v is a child of w if and only if w is the parent of v.

M.E.; O.E. cild "fetus, infant;" akin to Goth. kilthai "womb."

Farzand, from Mid.Pers. frazand "child;" Av. frazanti- "progeny, offspring," from fra- "forward, along," → pro-, + zan "to give birth;" → birth.

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.

<< < -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 awa azi bac bal Bar Bar Bay bea Bep Bet BIC bij bin bio bir bla bla blu blu bol Boo bou Bq bre bri bub B[e cal cal can car car Cas cat cau cel cen Cer cha cha cha che chi CI cir cir cla cle clo clu co- cob 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 coo cor cor cor cos cos cos cou cov cra cri cro cry cum cur cyc d'A dar dat DC dea dec dec dec def def deh Del den dep des det deu dia dif dif dif dim dip Dir dis dis dis dis dis div dom dos dou dri Dum dus dyn dyn ear eas ecl Edd eff Ein eje ele ele ele ele eli emb emi Enc ene ens eph epo equ equ eru eth Eul eve evo exc exc exi exo exp exp ext ext Fab fai Fan fea fem fer fie fil fir fir fla flo flu foc For for fos fra fre fre fro fun g m Gal gal gal gas gau gel gen geo geo geo gho gla gno gra gra gra gra Gre Gre gro gyr had hal har Har HD hea hel hel Her Her Hic hig hip hol hor hos hov Hub hun hyd hyd Hyd hyp IC ide ill ima imp imp inc inc ind ind inf inf inf inf inj ins ins int int int int int int int int inv inv ion iro Isl iso iso Jac jet jud jur kel Kep kil Kle 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 Mei Mer Mer met met Met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per pet pha Pho pho pho pho Pic Pis Pla pla pla pla Ple poa pol pol pol pol pop pos pos pow pra pre pre pre pri pri pri pro pro pro pro pro pro pro Pto pul puz 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 Rhe rid rig ris Roe Ros rot rub rut Sag sam sat sca sca Sch sci sea sec sec see sel sem sen ser Sgr sha shi sho sid sig sim sin Sir ske sli smo soc sol sol sol sol sol sou sou spa spe spe spe spe sph spi spl spu sta sta sta sta sta ste ste sti sto str Str sub sub sub sul sup sup sup sup sur sus sym syn sys Tam Tay tel ten Ter Tha the the the thi thr tib tid tim tok Tor tot tra tra tra tra Tri tri tro tru tur twi Typ ufo ult unc uni uni uni upl ura uti val var vec vel ver ver vil vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yea You zer zod > >>