An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 699
mass number
  عدد ِ جرمی   
adad-e jermi (#)

Fr.: nombre de masse   

The total number of → protons and → neutrons in the → atomic nucleus (symbol A). The mass number is written either after the → chemical element name or as a superscript to the left of an element's symbol. For example, the most common isotope of oxygen is oxygen-16, or 16O, which has 8 protons and 8 neutrons.

mass; → number.

mass outflow
  استچان ِ جرم   
ostacân-e jerm

Fr.: écoulement de masse   

The flowing out of mass through various processes from an object, for example in a star forming region or in a close binary.

mass; → outflow.

mass segregation
  سوایش ِ جرم   
savâyeš-e jerm

Fr.: ségrégation de masse   

A consequence of the → dynamical relaxation process in a gravitationally → bound system, such as a → star cluster or a → globular cluster, where massive and low-mass members occupy different volumes. Massive members sink toward the center, while less massive members tend to move farther away from the center.

mass; → segregation.

mass shift
  کیب ِ جرمی   
kib-e jermi


The portion of the isotope shift which results from the difference between the nuclear masses of different isotopes.

mass; → shift.

mass spectrometry
  بیناب‌سنجی ِ جرم   
binânsanji-ye jerm

Fr.: spectrométrie de masse   

An analytical technique for identification of chemical structures, determination of mixtures, and quantitative elemental analysis, in which ions are separated according to the mass/charge ratio and detected by a suitable detector.

mass; → spectrometry.

mass spectrum
  بیناب ِ جرم   
binâb-e jerm (#)

Fr.: spectre de masse   

A spectrum of charged particles, arranged in order of mass or mass-to-charge ratios. → mass spectrometry.

mass; → spectrum.

mass transfer
  تراوژ ِ جرم   
tarâvaž-e jerm

Fr.: transfert de masse   

The process in which the evolved member of a close binary system passes gaseous material to its companion star.

mass; → transfer.

mass transport
  ترابرد ِ جرم   
tarâbord-e jerm (#)

Fr.: transport de masse   

In fluid mechanics, the motion of a given amount of material carried by a fluid from one point to another.

mass; → transfer.

mass-energy equivalence
  هموگ‌ارزی ِ جرم-کاروژ   
hamug-arzi-ye jerm-kâruž

Fr.: équivalence masse-énergie   

The principle of interconversion of mass and energy, described by the → mass-energy relation.

mass; → energy; → equivalence.

mass-energy relation
  باز‌آنش ِ جرم-کاروژ   
bâzâneš-e jerm-kâruž

Fr.: relation masse-énergie   

The famous equation proposed by Einstein as a consequence of his special theory of relativity describing the equivalence of mass and energy: E = mc2, where E is energy, m is the equivalent amount of mass, and c is the velocity of light.

mass; → energy; → relation.

mass-luminosity ratio
  وابر ِ جرم-تابندگی   
vâbar-e jerm-tâbandegi

Fr.: rapport masse-luminosité   

The ratio of the mass of a system, expressed in solar masses, to its visual luminosity, expressed in solar luminosities. The Milky Way Galaxy has a mass-luminosity ratio in its inner regions of about 10, whereas a rich cluster of galaxies such as the Coma Cluster has a mass-luminosity ratio of about 200, indicating the presence of a considerable amount of dark matter.

mass; → luminosity; → ratio.

mass-luminosity relation
  باز‌آنش ِ جرم-تابندگی   
bâzâneš-e jerm-tâbandegi

Fr.: relation masse-luminosité   

A relationship between luminosity and mass for stars that are on the main sequence, specifying how bright a star of a given mass will be. Averaged over the whole main sequence, it has been found that L = M3.5, where both L and M are in solar units. This means, for example, that if the mass is doubled, the luminosity increases more than 10-fold.

mass; → luminosity; → relation.

porjerm (#)

Fr.: massif   

Consisting of or forming a large mass.

From M.Fr. massif (feminine massive) "bulky, solid," from O.Fr. masse "lump."

Porjerm, from por "full, much, very, too much," (Mid.Pers. purr "full;" O.Pers. paru- "much, many;" Av. parav-, pauru-, pouru-, from par- "to fill;" PIE base *pelu- "full," from *pel- "to be full;" cf. Skt. puru- "much, abundant;" Gk. polus "many," plethos "great number, multitude;" O.E. full) + jerm, → mass.

massive black hole
  سیه‌چال ِ پرجرم   
siyahcâl-e porjerm

Fr.: trou noir massif   

A black hole with a mass between millions and billions of solar masses residing in galactic nuclei. The mass of this type of black holes represents about 0.2% of the bulge mass. When matter is swallowed by the black hole, this gives rise to the tremendous energetic phenomena observed in quasars and active galactic nuclei.

massive; → black hole.

massive close binary
  دورین ِ کیپ ِ پرجرم   
dorin-e kip-e porjerm

Fr.: binaire serrée massive   

A → close binary system composed of two → massive stars.

massive; → close binary star.

massive halo
  هاله‌ی ِ پرجرم   
hâle-ye porjerm

Fr.: halo massif   

Spheroidal distribution of dark matter surrounding a galaxy.

massive; → halo.

massive star
  ستاره‌ی ِ پرجرم   
setâre-ye porjerm (#)

Fr.: étoile massive   

A star whose mass is larger than approximately 10 → solar masses. The → spectral types of massive stars range from about B3 (→ B star) to O2 (→ O star) and include → Wolf-Rayet stars as well as → Luminous Blue Variables. Massive stars are very rare; for each star of 20 solar masses there are some 100,000 stars of 1 solar mass. Despite this rarity, they play a key role in astrophysics. They are major sites of → nucleosynthesis beyond oxygen and, therefore, are mainly responsible for the → chemical evolution of galaxies. Due to their high ultraviolet flux and powerful → stellar winds, they bring about interesting phenomena in the → interstellar medium, like → H II regions, → turbulence, → shocks, → bubbles, and so on. Massive stars are progenitors of → supernovae (→ type Ia, → type Ic and → type II), → neutron stars, and → black holes. The formation processes of massive stars is still an unresolved problem. For massive stars the → accretion time scale is larger than the → Kelvin-Helmholtz time scale. This means that massive stars reach the → main sequence while → accretion is still going on.

massive; → star.

mastar (#)

Fr.: maître   

1) A person with the ability or power to use, control, or dispose of something.
2) An employer of workers or servants.
3) The male head of a household (

M.E. maistre, maister, from O.E. magister, from L. magister "chief, head, director, teacher," ultimately from PIE root *meg- "great," cf. Pers. meh-, as below.

(Aftari) Mastar "elder; larger," (Dari Kermân) mastar "leader, guide," variants (Aftari, Tafreši) mester "elder; great," massar "large, great, high," from (Nâini, Sangesari, Dari Yazd, Kermâni) mas "great, large," variant of meh "great, large, principal," cognate with L. magister "chief, head, director, teacher;" → Big Bang, + comparative suffix -tar.


Fr.: match, partie   

A game or contest in which two or more contestants or teams oppose each other (

Originally "one of a pair, an equal;" O.E mæcca, "companion, mate, one of a pair, wife, husband, an equal," from gemæcca; cf. O.S. gimaco "fellow, equal," O.H.G. gimah "comfort, ease," M.H.G. gemach "comfortable, quiet," Ger. gemach "easy, leisurely."

Kâd, from Mid.Pers. kâdag "game," Sogd. kâtak "game, play;" cf. Kurd. (Sorani) kâya "game," Zazaki kây, Abyâneyi, Anâraki, Nâini kâye, Qohrudi kâda, Shamerzâdi ke, Zefrehi "game, play;" Av. kā- "to take pleasure, desire;" Skt. kā- "to desire, wish."

mâdar (#)

Fr.: mère, matrice   

The body of the → planispheric astrolabe which is a thin circular plate, with a hole in the center. It has a thicker, raised, and graduated edge, called the → limb. The hollow of the mater holds the → tympanum and the rotating → rete. The upper part of the mater carries a jointed ring, called the → throne. By slipping one's thumb into the ring, one raises the instrument so that its weight and symmetrical design keeps it perpendicular to the ground. On the back of the mater are engraved several circular scales (online museo galileo, VirtualMuseum).

From L. mater, → mother.

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