An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < abs atm con dat ext int mou poi ref tel > >>

Number of Results: 192 Search : tin
integrating factor
  کروند ِ درستالنده   
karvand-e dorostâlandé

Fr.: facteur intégrant   

A function that converts a → differential equation, which is not exact, into an → exact differential equation. This is done by multiplying all terms of the original equation by the integrating factor.

integrate; → factor.

interacting binary
  دورین ِ اندرژیرنده   
dorin-e andaržirandé

Fr.: binaire en interaction   

A binary star system in which mass transfer between the components takes place. → contact binary; → Roche lobe.

Interacting, adj. of → interact; → binary.

interacting galaxies
  کهکشان‌های ِ اندرژیرنده   
kahkešânhâ-ye andaržandé

Fr.: galaxies en interaction   

Galaxies that are close enough for their mutual gravitational attraction to produce perturbed shapes or extruded filaments of stellar material, called → tidal tails. Most galaxies are in clusters, and gravitational interactions between them are common.

Interacting, adj. of → interact; → galaxy.


Fr.: intéressant   

Inspiring interest, holding the attention.

Adj. from → interest.

interstellar extinction
  خاموشی ِ اندر-اختری   
xâmuši-ye andaraxtari

Fr.: extinction interstellaire   

The dimming of light traveling in the interstellar space due to the combined effects of absorption and scattering by interstellar dust particles. Interstellar extinction increases at shorter (bluer) wavelengths, resulting in → interstellar reddening.

interstellar; → extinction.


Fr.: durable   

Continuing or remaining for a long time; enduring.

last; → -ing.

limiting magnitude
  برز ِ حد   
borz-e hadd

Fr.: magnitude limite   

The faintest magnitude reachable by an instrument.

limit; → magnitude.

line blanketing
  پتومندی ِ خط   
patumandi-ye xatt


In stellar atmosphere models, the effect of metallic lines on the atmospheric structure of stars. The additional opacities of thousands of metallic lines alter the radiative transfer, leading to changes in the temperature. The emergent spectrum is consequently modified.

line-blanketed model.


Fr.: liste, cotation, listing   

1) A list; the act of compiling a list; something listed.
2) Computers: A display or printed list of lines in a program or digital data.

list; → -ing.

logarithmic extinction
  خاموشی ِ لگاریتمی   
xâmuši-ye logâritmi

Fr.: extinction logarithmique   

Same as → reddening coefficient.

logarithmic; → extinction.

Lyman alpha emitting galaxy (LAEs)
  کهکشان ِ گسیلنده‌ی ِ لایمن-آلفا   
kahkešân-e gosilande-ye Lyman-alpha

Fr.: galaxie émettrice de Lyman alpha   

A galaxy belonging to an important population of low mass → star-forming galaxies at → redshift z > 2. Their number increases with redshift. A large fraction of the → dwarf starburst galaxies during the → reionization epoch may be intrinsic LAEs, but their Lyα photons can be scattered by the → neutral hydrogen (H I) in the → intergalactic medium (IGM), which makes Lyα line a powerful probe of reionization. These high-z LAEs have low → metallicity, low stellar masses, low dust → extinction, and compact sizes. The current best nearby analogs of high-z LAEs are → Green Pea galaxies (Yang et al, 2017, arxiv/1706.02819 and references therein).

Lyman alpha line; → emit; → -ing; → galaxy.

Lyman continuum
  پیوستار ِ لایمن   
peyvastâr-e Lyman (#)

Fr.: continuum de Lyman   

A continuous range of wavelengths in the spectrum of hydrogen at wavelengths less than the → Lyman limit. The Lyman continuum results from transitions between the → ground state of hydrogen and → excited states in which the single electron is freed from the atom by photons having an energy of 13.6 eV or higher.

Lyman; → continuum.

Lyman continuum escape
  گریز ِ پیوستار ِ لایمن   
goriz-e peyvastâr-e Lyman

Fr.: échappement du continuum de Lyman   

The process whereby → Lyman continuum photons produced by → massive stars escape from a galaxy without being absorbed by interstellar material. Some observations indicate that the Lyman continuum escape fraction evolves with → redshift.

Lyman; → continuum; → escape.

magnetic splitting
  فاقش ِ مغناتیسی   
fâqeš-e meqnâtisi

Fr.: dédoublement magnétique   

A process whereby the (internal) → magnetic field of a star modifies the → pulsations by lifting some of its degeneracy. Instead of just one pulsation frequency, a multiplet of frequencies is then observed. This effect was proposed as a possible explanation for the observed frequency pattern of → Beta Cephei. In practice, the magnetic splitting is difficult to observe, because of the very small expected frequency difference between the peaks. However, when unaccounted for, it may lead to a wrong mode identification. The current best candidate to detect magnetic splitting is → HD 43317, since this star displays two close frequency patterns (Buysschaert et al., 2017, astro-ph/1709.02619).

magnetic; → splitting.

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.

mass extinction
  خاموشی ِ انبوه   
xâmuši-ye anbuh

Fr.: extinction en masse   

An event in the history of life on Earth in which large numbers of species (sometimes more than 90% of some species) vanish in a relatively short period of time. In spite of controversy, it is generally recognized that there have been at least six major mass extinctions. These occurred in the late Cambrian (500 million years ago), in the late Ordovician (440 million years ago), in the late Devonian (365 million years ago), at the end of the Permian (245 million years ago), in the late Triassic (208 million years ago), and at the end of the Cretaceous (65 million years ago).

mass; → extinction.


Fr.: rencontre   

1) The act of coming together.
2) An → assembly or conference of persons for a specific purpose (

meet; → -ing.

melting point
  نقطه‌ی ِ گداز   
noqte-ye godâz (#)

Fr.: point de fusion   

The temperature at which a solid changes to a liquid.

melting; → point.


Fr.: microinformatique   

The area of computer science dealing with the use and development of microcomputers, and related peripheral devices and softwares. Also microinformatics.

micro-; → compute.

Riz-, → micro-; azdâyik, → informatics.

mirror testing
  آزمون ِ آینه   
âzmun-e âyené (#)

Fr.: test d'un miroir   

The observation and measurement of the flatness of a mirror surface. The process generally is done before coating so as not to damage the delicate coated surface. For coated and curved surfaces, non-contact methods are often employed, generally using interference techniques.

mirror; → test.

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