An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < A-t pro Typ > >>

Number of Results: 50 Search : type
A-type star
  ستاره‌ی ِ گونه‌ی ِ A   
setâre-ye gune-ye A

Fr.: étoile de type A   

Same as → A star.

A, letter of alphabet used in the → Harvard classification; → type; → star.

Algol-type variables
  ورتندگان ِ الغولگونه   
vartandegân-e Alqulguné

Fr.: variables de type Algol   

The same as eclipsing binary stars, the prototype of which is Algol.

Algol; → variable.

sarnemun (#)

Fr.: archétype   

The original pattern or model from which all things of the same kind are copied or on which they are based; a model or first form; prototype (

arche-; → type.

B-type asteroid
  سیارک ِ گونه‌ی ِ B   
sayyârak-e gune-ye B

Fr.: astéroïde de type B   

A division of → C-type asteroids whose members have relatively low albedos (0.04 to 0.08) and the → ultraviolet absorption below 0.5 μm is small or absent. Examples include → 2 Pallas, 379 Huenna (diameter 62 km), and → 101955 Bennu.

type; → asteroid.

B-type star
  ستاره‌ی ِ گونه‌ی ِ B   
setâre-ye gune-ye B

Fr.: étoile de type B   

Same as → B star.

B, letter of alphabet used in the → Harvard classification; → type; → star.

C-type asteroid
  سیارک ِ گونه‌ی ِ C   
sayârak-e gune-ye C

Fr.: astéroïde de type C   

An → asteroid that belongs to the family of → carbonaceous asteroids. They are → depleted in → hydrogen and → helium, have chemical ratios akin to solar composition, and show low → albedo (0.03-0.09). C-type asteroids are the most common variety, forming around 75% of known asteroids. They inhabit → main belt's outer regions.

C stands for → carbonaceous; → type; → asteroid.

D-type ionization front
  پیشان ِ یونش ِ گونه‌ی ِ D   
pišân-e yoneš-e gune-ye D

Fr.: front d'ionisation de type D   

An → ionization front of → H II regions whose expansion speed is comparable to the → sound speed in the gas (~ 10 km/sec for hydrogen at 104 K). A D-type ionization front results from → R-type ionization front when its propagation speed decreases as the volume of gas ahead of the ionization front grows. If front velocity is equal to a lower limit (C12 / 2C2, where C1 and C2 are the sound speed ahead and behind the front respectively), the front is called D critical.

D referring to a dense gas; → type; → ionization; → front.

E-type chondrite
  کوندریت ِ گونه‌ی ِ E   
kondrit-e gune-ye E

Fr.: chondrite de type E   

Same as → enstatite chondrite.

enstatite; → type; → chondrite.

early-type galaxy (ETG)
  کهکشان ِ گونه‌ی ِ آغازین   
kahkešân-e gune-ye âqâzin

Fr.: galaxie de type précoce   

In the → Hubble classification, galaxies on the left part of the → Hubble sequence. Early-type galaxies tend to have redder colors, higher average surface brightnesses, and lower → neutral hydrogen content than → late-type galaxies. This terminology is based on the obsolete and erroneous idea that → elliptical and → lenticular galaxies might be evolutionary precursors to → spiral and → barred spiral galaxies.

early; → type; → galaxy.

early-type star
  ستاره‌ی ِ گونه‌ی ِ آغازین   
setâre-ye gun-ye âqâzin (#)

Fr.: étoile de type précoce   

Hot, luminous stars of → spectral type O, B, A, and F0 to F5. They were originally thought, wrongly, to be at an earlier stage of evolution than → late-type stars. See also → spectral classification.

early; → type; → star.

F-type star
  ستاره‌ی ِ گونه‌ی ِ F   
setâre-ye gune-ye F

Fr.: étoile de type F   

A star whose spectrum is characterized by strong → absorption lines of ionized → calcium, Ca II (→ H and K lines), which become much stronger than the hydrogen lines of the → Balmer series. A multitude of fainter metallic lines are also present. Ca II lines strengthen to later types. → Main sequence F stars, of which → Procyon is an example, have a → surface temperature of 6,000 to 7,400°C and a mass of 1.1 to 1.4 → solar masses (Habets & Heintze, 1981, AASS 46, 193).

B, letter of alphabet used in the → Harvard classification; → type; → star.

G type star
  ستاره‌ی ِ گونه‌ی ِ G   
setâre-ye gune-ye G

Fr.: étoile de type G   

A yellowish star whose surface temperature is about 6000 K and its spectrum is dominated by H and K lines of ionized calcium (Ca II 3968 Å and 3934 Å).

G from the alphabetical sequence of spectral types; → type; → star.

G-type asteroid
  سیارک ِ گونه‌ی ِ G   
sayyârak-e gune-ye G

Fr.: astéroïde de type G   

A relatively uncommon → carbonaceous carbonaceous asteroid whose spectrum contains a strong → ultraviolet  → absorption feature below 0.5 μm (→ Tholen classification). In the → SMASS classification it corresponds to the Cg and Chg types , depending on the presence or absence (respectively) of the absorption feature at 0.7 μm. The most remarkable "asteroid" in this type is → Ceres (now classified as a → dwarf planet).

type; → asteroid.

G-type star
  ستاره‌ی گونه‌ی ِ G   
setâre-ye gune-ye G

Fr.: étoile de type G   

Same as → G star.

G star; → type.

late-type galaxy (LTG)
  کهکشان ِ گونه‌ی ِ فرجامین   
kahkešân-e gune-ye farjâmin

Fr.: galaxie de type tardif   

In the → Hubble classification, a galaxy on the left part of the → Hubble sequence. See also → early-type galaxy.

late; → type; → galaxy.

late-type star
  ستاره‌ی ِ گونه‌ی ِ فرجامین   
setâre-ye gune-ye farjâmin

Fr.: étoile de type tardif   

A star of → spectral type K, M, S, or C, with a surface temperature lower than that of the Sun. → early-type star. See also → spectral classification.

late; → type; → star.

M-type asteroid
  سیارک ِ گونه‌ی ِ M   
sayârak-e gune-ye M

Fr.: astéroïde de type M   

A type of → asteroid that consists of metallic → iron and displays high → albedo (0.10-0.18). M-type asteroids inhabit the middle part of the → asteroid belt.

M for → metallic; → type; → asteroid.

Magellanic type galaxy
  کهکشان ِ گونه‌ی ِ ماژلانی   
kahkešân-e gune-ye Magellani

Fr.: galaxie de type magellanique   

A → metal-poor, → irregular galaxy like the → Large Magellanic Cloud or the → Small Magellanic Cloud. Other examples are: NGC 4449, NGC 4214, and NGC 3109.

Magellanic; → type; → galaxy.

n-type conductivity
  هازندگی ِ گونه‌ی ِ n   
hâzandegi-ye gune-ye n

Fr.: conductivité de type n   

The conductivity in a semiconductor caused by a flow of electrons, whereas p-type conductivity is caused by a flow of holes.

n standing for → negative; → type; → conductivity.

O-type star
  ستاره‌ی ِ گونه‌ی ِ O   
setâre-ye gune-ye O

Fr.: étoile de type O   

Same as → O star.

O, letter of alphabet used in the → Harvard classification; → type; → star.

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