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: 732
regression coefficient
  همگر ِ وایازش   
hamgar-e vâyâzeš (#)

Fr.: coefficient de régression   

The slope of the straight line that most closely relates two correlated variables.

regression, → coefficient.

regression curve
  خم ِ وایازش   
xam-e vâyâzeš

Fr.: courbe de régression   

A curve representing a non-linear relationship between two or more → variables.

regression, → curve.

regression equation
  هموگش ِ وایازش   
hamugeš-e vâyâzeš

Fr.: équation de régression   

A mathematical expression that describes the relationship between two or more variables. It indicates the nature of the relationship and, in particular, the extent to which one can predict some variables by knowing others.

regression, → equation.

regression function
  کریای ِ وایازش   
karyâ-ye vâyâzeš

Fr.: fonction de régression   

A mathematical function that describes the relationship between two or more variables in a set of data.

regression, → function.

regression line
  خط ِ وایازش   
xatt-e vâyâzeš

Fr.: droite de régression   

The curve representing a → linear regression. It is a line drawn through a set of data that summarizes the relationship between the → variables being studied.

regression, → line.

regression of the nodes
  پسرفت ِ گره‌ها، ~ گوزهرها   
pasraft-e gerehhâ , ~ gowzahrhâ

Fr.: régression des noeuds   

The slow motion of the → nodes of the Moon's orbit in the opposite direction to the Moon's movement. This westward motion, caused by perturbations of other bodies, mainly the Earth and Sun, has a rate of 19.35 degrees per year, making one rotation in 18.6 years.

regression; → node.

regular
  ۱) باسامان؛ ۲) رزن‌مند   
1) bâsâmân (#); 2) razan-mand

Fr.: ordonné, régulier   

1) Evenly or uniformly arranged in space or time; orderly; well-ordered.
Math.: Of a polygon, having all sides and angles equal.
2) Conforming to some accepted rule, discipline, etc.

M.E. reguler, from M.Fr., from O.Fr. reguler, from L.L. regularis "continuing rules for guidance," from L. regula "rule," cognate with Pers. râst, → right.

1) Bâsâmân, from bâ- "with, having" (→ hypo- + sâmân "order, arrangement, disposition; boundary, limit," Lârestâni sâmon "sign or mark separating one field from another," Gilaki, Tabari šalmân "a straight peace of wood or beam, post;" Mid.Pers. sâmânak, sahmân "limit;" loaned into Arm. sahmân; cf. Skt. sīmān-, sīmā- "boundary, border, limit."
2) Razan-mand, from razan, → rule, + -mand a possession suffix.

regular function
  کریای ِ باسامان   
karyâ-ye bâsâmân

Fr.: fonction régulière   

A function of a complex variable which is single-valued in a domain and which has a finite derivative at every point.

regular; → function.

regular galaxy
  کهکشان ِ باسامان   
kahkašân-e bâsâmân

Fr.: galaxie régulière   

A galaxy which has a uniformly arranged, symmetrical morphology such as a spiral or elliptical galaxy. Opposite of → irregular galaxy.

regular; → galaxy.

regular reflection
  بازتاب ِ باسامان   
bâztâb-e bâsâmân

Fr.: réflexion régulière   

The reflection of light when the reflecting surface is very smooth and the reflected rays bounce off parallel to each other. Opposite of → diffuse reflection; same as → specular reflection.

regular; → reflection.

regular satellite
  بنده‌وار ِ باسامان، ماه ِ ~   
bandevâr-e bâsâmân, mâh-e ~

Fr.: satellite régulier   

A satellite that revolves around its planet in an equatorial orbit of low or moderate eccentricity close to the planet. One example of a regular satellite system is the Galilean satellites of Jupiter.

regular; → satellite.

regulate
  رزنیدن   
razanidan

Fr.: réguler   

To control, direct, or adjust by a rule, principle, method, etc.

From L.L. regulatus, p.p. of regulare "to control by rule, direct," from L. regula, cognate with Pers. râstright.

Razanidan, verbal form of razan, → rule, cognate with L. regula.

regulated
  رزنیده   
razânidé

Fr.: régulé, réglementé   

Controlled or governed according to a rule or principle or law.

Past participle of → regulate.

regulation
  رزنش   
razaneš

Fr.: régulation   

1) The act of regulating; the state of being regulated.
2) A law, rule, or other order prescribed by authority.
3) Electronics: The degree by which a voltage source is held near its no-load amplitude when a load is applied.

Verbal noun of → regulate.

regulator
  رزنگر   
razângar

Fr.: régulateur   

A person or thing that regulates.
A governor mechanism for regulating the flow of fuel, steam, etc., to an engine in order to maintain constant speed under varying load or resistance.

Agent noun of → regulate.

Regulus (α Leonis)
  شیردل   
Širdel

Fr.: Régulus   

The brightest star in the constellation → Leo (V = 1.35). Regulus is approximately 77.5 light-years from Earth. It is a triple star system composed of a hot, bluish-white star with a pair of small, faint companions. The main star (Regulus A) is a main sequence of type B7, with a luminosity 140 times brighter than the Sun. Its equatorial rotation speed being 317 kilometers per second, the fast rotation distorts Regulus into an oblate spheroid with an equatorial diameter about 30 percent larger than the polar diameter. As a result, the poles, with a temperature of 15,400 Kelvin, are much hotter than the equator, which glows at 10,200 Kelvin.

L., literally "little king," diminutive of rex "king," related to regere "to keep straight, guide, lead, rule," from PIE base *reg- "to rule, to lead straight, to put right;" akin to Pers. râst "right, straight, correct," → right.

Širdel, literally "the Lion's heart," on the model of Ar. Qalb al-Asad (قلب‌الاسد), from šir "lion;" Mid.Pers. šagr "lion" + del "heart;" Mid.Pers. dil; Av. zərəd- "heart;" cf. Skt. hrd-; Gk. kardia; L. cor Arm. sirt; PIE base *kerd- "heart;" O.E. heorte; E. heart; Ger. Herz; Bret. kreiz "middle."

reionization
  بازیونش   
bâzyoneš

Fr.: reionisation   

1) The act or process of reionizing a gas; an instance of this action.
2) The → ionization of → neutral hydrogen atoms formed during → recombination epoch in the → early Universe. See also → reionization epoch.

re-; → ionize.

reionization epoch
  زیمه‌ی ِ بازیونش   
zime-ye bâzyoneš

Fr.: époque de réionisation   

An early epoch in the → Universe's history, but after the → recombination epoch, when the → first stars formed and their → ultraviolet light began to ionize the → neutral hydrogen gas that filled the Universe. The epoch of reionization is estimated to last between → redshifts of 12 to 6 (or when the Universe had between 2 and 5% of its age). Reionization marks the end of the → Dark Age in cosmic history.

reionization; → epoch.

reionize
  بازیونیدن   
bâzyonidan

Fr.: reioniser   

1) To become → ionized again.
2) To → ionize again.

re-; → ionize.

Reissner-Nordstrom black hole
  سیه‌چال ِ رایسنر-نوردستروم   
siyah câl-e Reissner-Nordström

Fr.: tou noir de Reissner-Nordström   

A type of electrically charged → black hole that is spherically symmetric and non-rotating. Another type of such objects is the → Kerr-Newman black hole.

Named after the German physicist Hans Jacob Reissner (1874-1967) in 1916 and the Finnish Gunnar Nordstrom (1881-1923) in 1918 independently worked out solutions different from those of Schwarzschild; → black hole.

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