An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 22 Search : main
codomain
  هم-دمن   
ham-daman

Fr.: ensemble d'arrivée   

The set of values that a → function is allowed to take (i.e. may possibly come out of a function), as opposed to the → range.

co-; → domain.

domain
  دمن   
daman

Fr.: domaine   

1) Math.: The set of x values that can go into a function f(x). Compare with → codomain and → range.
2) Ferromagnetism: → magnetic domain.

From M.Fr. domaine "domain, estate," from O.Fr. demaine "lord's estate," from L. dominium "property, dominion," from dominus "master of a household," from domus "house;" cognate with Pers. dam, as below; Gk. domos "house;" O.C.S. domu , Russ. dom "house;" Lith. dimstis "enclosed court, property;" O.E. timber "building, structure"); PIE base *dem-/*dom- "to build."

Daman, from Av. dəmāna- "house," dami "in the house;" cf. Sogd. δmān "house;" Mod.Pers. dam "wealth, means of comfort" (often as dam o dastgâh); "threshold, doorway;" Gilaki dâmana "ceiling;" Sariqoli waδem, Yazghulami wəδem "ceiling;" Skt. dám- "house;" Proto-Iranian *damH- "to build;" Gk. demo "I build;" L. domus "house," as above.

domain wall
  دیوار ِ دمن   
divâr-e daman

Fr.: paroi de domaine, mur ~ ~   

In a → ferroelectric substance, the transition layer between two → domains magnetized in different directions. It is of finite thickness ans has nonuniform → magnetization.

domain; → wall.

galaxy main sequence
  رشته‌ی ِ فریست ِ کهکشانها   
rešte-ye farist-e kahkešânhâ

Fr.: séquence principale des galaxies   

A scaling relation between the → star formation rate (SFR) in galaxies and the total stellar mass (M*) of the galaxies. This relation, colloquially called the "galaxy main sequence," extends over several orders of magnitudes in M* and out to → high redshifts, with a modest scatter of ~ 0.3 dex which includes both intrinsic scatter and measurement uncertainties. The existence of such tight scatter at all observed epochs suggests that most galaxies assembled their stellar mass fairly steadily rather than predominantly in → starburst episodes, implying that → mergers have a sub-dominant contribution to the global star formation history (Wuyts et al., 2011 ApJ 742, 96).

galaxy; → main; → sequence.

lower main sequence
  رشته‌ی ِ فریست ِ زیرین   
rešte-ye farist-e zirin

Fr.: séquence principale inférieure   

A → main sequence star whose mass is less than 1.5 Msun. Lower main sequence stars generate their energy chiefly through the → proton-proton chain. The core is surrounded by a → radiative zone above which lies a → convective envelope. In such stars the → opacity at the surface is high because of the low → surface temperature. Therefore, radiation cannot carry all the radiation because of high opacity. Thus, energy transfer takes place by → convection to the outer layer.

lower; → main; → sequence.

magnetic domain
  دمن ِ مغناتیسی   
daman-e meqnâtisi

Fr.: domaine magnétique   

Any of several microscopic areas in a → ferromagnetic material that possesses a net → magnetic field, because electron spins are aligned in the same direction. In the absence of an external magnetic field, the directions of the magnetization vectors of the separate domains do not coincide and the resultant magnetization of the whole body may be zero.

magnetic; → domain.

main
  فریست   
farist

Fr.: principal   

Chief in size, extent, or importance; leading; → principal.

From M.E. meyn, mayn "strength, power," from O.E. mægen "power, strength, force," from P.Gmc. *maginam- "power," from *mag- "to be able, have power."

Farist, literally "foremost" (cf. Mid.Pers. frahist "main, principal, first, much"), from far-, Mid.Pers. fra-; O.Pers. fra- "forward, forth;" Av. frā "forth," pouruua- "first"; cf. Skt. pūrva- "first," pra- "before, formerly;" Gk. pro; L. pro; O.E. fyrst "foremost," superlative of fore, E. fore + -est superlative suffix, Mid.Pers. -ist, -išt-; Av. -išta-, cf. Skt. -istha-, Gk. -istos, O.H.G. -isto, -osto, O.E. -st, -est, -ost.

main beam
  لپ ِ فریست   
lap-e farist

Fr.: lobe principal   

Same as → main lobe.

main; → beam.

main belt
  کمربند ِ فریست   
kamarband-e farist

Fr.: ceinture principale   

The area between → Mars and → Jupiter where most of the → asteroids in our → solar system are found.

main; → belt.

main diagonal
  تراکنج ِ فریست   
tarâkonj-e farist

Fr.: diagonale principale   

In the n x n → matrix , the entities a11, a22, ..., ann.

main; → diagonal.

main lobe
  لپ ِ فریست   
lap-e farist

Fr.: lobe principal   

The lobe in the reception pattern of a radio telescope that includes the region of the maximum received power. Also called major lobe and main beam.

main; → lobe.

Main Ring
  حلقه‌ی ِ فریست   
halqe-ye farist

Fr.: anneau principal   

A thin strand of material encircling Jupiter; the main component in → Jupiter's ring system of three parts. The diffuse innermost boundary begins at approximately 123,000 km. The main ring's outer radius is found to be at 128,940 km,

main; → ring.

main sequence
  رشته‌ی ِ فریست   
ršte-ye farist

Fr.: séquence principale   

An evolutionary stage in the life of a star when it generates its energy by the conversion of hydrogen to helium via → nuclear fusion in its core. Stars spend 90% of their life on the main sequence. On the → Hertzsprung-Russell diagram it appears as a track running from top left (high temperature, high luminosity, high mass) to lower right (low temperature, low luminosity, low mass). See also → zero age main sequence (ZAMS), → terminal age main sequence (TAMS).

main; → sequence.

main-sequence fitting
  سزکرد ِ رشته‌ی ِ فریست   
sazkard-e reshteh-ye farist

Fr.: ajustement par la séquence principale   

The method of determining the distance to a star cluster by overlaying its main sequence on the theoretical zero-age main sequence and noting the difference between the cluster's apparent magnitude and the zero-age main sequence's absolute magnitude.

main sequence; → fitting.

main-sequence turnoff
  رهگشت ِ رشته‌ی ِ فریست   
rahgašt-e rešte-ye farist

Fr.: tournant final de la séquence principale   

The point on the → Hertzsprung-Russell diagram of a star cluster at which stars begin to leave the → main sequence and move toward the → red giant branch. The main-sequence turnoff is a measure of age. In general, the older a star cluster, the fainter the main-sequence turnoff. Same as → turnoff point.

main sequence; → turnoff.

post-main sequence star
  ستاره‌ی ِ پسا-رشته‌ی ِ فریست   
setâre-ye pasâ-rešte-ye farist

Fr.: étoile post séquence principale   

A star that has evolved off the → main sequence.

post-; → main sequence; → star.

pre-main sequence binary
  درین ِ پیش-رشته‌ی ِ فریست   
dorin-e piš-rešte-ye farist

Fr.: binaire pré-séquence principale Markarian's Chain   

A → binary system whose components are → pre-main sequence stars.

pre-; → main sequence; → binary.

pre-main sequence B[e] star (HAeB[e])
  ستاره‌یِ B[e]ی ِ پیش-رشته-ی فریست   
setâre-ye B[e]-ye piš-rešte-ye farist

Fr.: étoile B[e] pré-séquence principale   

A → Herbig AeBe star displaying → forbidden emission lines in its spectrum.

pre-; → main; → sequence; → B[e] star.

pre-main sequence star
  ستاره‌ی ِ پیش-رشته‌ی ِ فریست   
setâre-ye piš-rešte-ye farist

Fr.: étoile pré-séquence principale   

A star that evolves in the → Hayashi phase and has not yet reached the → zero-age main sequence.

pre-; → main sequence, → star.

terminal age main sequence (TAMS)
  رشته‌ی ِ فریست با سن ِ پایانی   
rešte-ye farist bâ senn-e pâyâni

Fr.: séquence principale d'âge terminal   

The locus of stars on the → Hertzsprung-Russell diagram that are at the point of exhausting hydrogen in their cores. TAMS forms the upper luminosity boundary of the → main sequence strip. See also → zero age main sequence (ZAMS).

terminal; → age; → main; → sequence.

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