# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 13176 Search : in
 Newtonian   نیوتنی   Newtoni (#)Fr.: newtonien   Of or pertaining to Sir Isaac Newton or to his theories or discoveries.Newtonian, from → Newton + -ian a suffix forming adjectives. Newtonian approximation   نزدینش ِ نیوتنی   nazdineš-e NewtoniFr.: approximation newtonienne   A particular solution of the → general relativity when the → gravitational mass is small. The → space-time is then approximated to the → Minkowski's and this leads to → Newtonian mechanics. Newtonian constant of gravitation   پایای ِ گرانش ِ نیوتن   pâyâ-ye gerâneš-e NewtonFr.: constante de la gravitation newtonienne   Same as the → gravitational constant.→ Newtonian; → constant; → gravitation. Newtonian cosmology   کیهان‌شناسی ِ نیوتنی   keyhânšenâsi-ye NewtoniFr.: cosmologie newtonienne   The use of → Newtonian mechanics to derive homogeneous and isotropic solutions of → Einstein's field equations, which represent models of expanding Universe. The Newtonian cosmology deviates from the prediction of → general relativity in the general case of anisotropic and inhomogeneous models.→ Newtonian; → cosmology. Newtonian fluid   شاره‌ی ِ نیوتنی   šârre-ye NewtoniFr.: fluide newtonien   Any → fluid with a constant → viscosity at a given temperature regardless of the rate of → shear.→ Newtonian; → fluid. Newtonian focus   کانون ِ نیوتن، ~ نیوتنی   kânun-e Newton, ~ NewtoniFr.: foyer de Newton   The focus obtained by diverting the converging light beam of a reflecting telescope to the side of the tube.→ Newtonian; → focus. Newtonian limit   حد ِ نیوتنی   hadd-e NewtoniFr.: limite newtonienne   The limit attained by → general relativity when velocities are very smaller than the → speed of light or gravitational fields are weak. This limit corresponds to the transition between general relativity and the → Newtonian mechanics. See also → Newtonian approximation.→ Newtonian; → limit. Newtonian mechanics   مکانیک ِ نیوتنی   mekânik-e Newtoni (#)Fr.: mécanique newtonienne   A system of mechanics based on → Newton's law of gravitation and its derivatives. Same as → classical mechanics.→ Newtonian; → mechanics. Newtonian potential   توند ِ نیوتنی   tavand-e NewtoniFr.: potentiel newtonien   A potential in a field of force obeying the inverse-square law such as → gravitational potential.→ Newtonian; → potential. Newtonian principle of relativity   پروز ِ بازانیگی ِ نیوتن   parvaz-e bâzânigi-ye NewtonFr.: principe de relativité de Newton   The Newton's equations of motion, if they hold in any → reference frame, they are valid also in any other reference frame moving with uniform velocity relative to the first.→ Newtonian; → principle; → relativity. Newtonian relativity   بازانیگی ِ نیوتنی   bâzânigi-ye NewtoniFr.: relativité newtonienne   The laws of physics are unchanged under → Galilean transformation. This implies that no mechanical experiment can detect any intrinsic diff between two → inertial frames. Same as → Galilean relativity.→ Newton; → relativity. Newtonian telescope   دوربین ِ نیوتن، تلسکوپ ِ ~   durbin-e Newton, teleskop-e ~Fr.: télescope de Newton, ~ newtonien   A telescope with a concave paraboloidal objective mirror and a small plane mirror that reflects rays from the primary mirror laterally outside the tube where the image is viewed with an eyepiece.→ Newtonian; → telescope. next   پدا   podâFr.: prochain   Immediately following in time, order, place, and so on.M.E., from O.E. next, nehst, niehsta, nyhsta "nearest, closest," superlative of neah "nigh" + superlative suffix. Cognate with Du. naast "next," O.H.G. nahisto "neighbor," Ger. nächst "next."Podâ, literally "placed after," from *upada-, from *upa- "near, next, after," + *dâ- "to place, put," → thesis; cf. Baluci pôši "the day after tomorrow," from pô- contraction of *upa- + *aušah- "dawn," + → aurora, + suffix -i; cf. also Baluci godâ (from *uidâ-?) "then, next;" Bašâgardi, Baluci randâ "next, then." NGC 1275      NGC 1275Fr.: NGC 1275   A → Seyfert galaxy, which is the central, dominant member of the large and relatively nearby → Perseus cluster of galaxies. A powerful source of X-rays and radio emission, NGC 1275 accretes matter (→ accretion) as intercluster material falls into it, ultimately feeding a → supermassive black hole (SMBH) at the galaxy's core. NGC 1275, hosts a narrow-line radio source, Perseus A (3C 84), which interacts with the intracluster gas through its jets and bipolar outflows.NGC, → New General Catalogue. NGC 346      NGC 346Fr.: NGC 346   A prominent → star cluster, and the ionizing core of giant → H II region → N66 in the → Small Magellanic Cloud galaxy. NGC 346 hosts the largest sample of young, → massive stars in the whole SMC, containing 33 → O-type stars among which 11 are of type O6.5 or earlier. This is young massive star cluster with an estimated age of about 3 million years.346, a serial number in the → New General Catalogue. NGC 3603      NGC 3603Fr.: NGC 3603   The most massive and luminous visible → starburst region in the Galaxy. This is our local → giant H II region lying at a distance of about 6-7 kpc in the → Carina arm (→ right ascension = 11h, → declination = -61°). Its central starburst cluster hosts the largest known concentration of extremely young, mostly unevolved → high-mass stars in the Galaxy. With an age of only 1-2 Myr for its most massive stars, NGC 3603 is one of the youngest starburst clusters known. It has about 40 known → O stars and → W-R stars, producing a → Lyman continuum flux of 1051 s-1, about 100 times the ionizing power of the Orion → Trapezium cluster. The OB stars contribute to more than 2000 → solar masses to the cluster mass. With a bolometric luminosity over 107→ solar luminosities, NGC 3603 has about 10% of the luminosity of → 30 Doradus and looks in many respects very similar to its core, → R136. A total mass of 7,000 solar masses is measured in the inner 1 pc from the cluster center, whereas the → low-mass stars extend out to at least 5 pc. The mass segregated core of the cluster, with 105 solar masses per pc3, displays the highest local stellar density outside the Galactic Center region. The spectral analysis of the W-R like massive component in the cluster core (→ HD 97950) suggests a → metallicity close or equal to solar (See, e.g., Melena et al. 2008, AJ 135, 878, and references therein).3603, a serial number in the → New General Catalogue. NGC 3603-A1      NGC 3603-A1Fr.: NGC 3603-A1   A → binary star lying in the core of the Galactic → giant H II region  → NGC 3603. NGC 3603-A1 is double-eclipsing → Wolf-Rayet binary of type → WN6ha with an orbital period of 3.77 days. Their masses have been derived to be M1 = (116 ± 31) Msun for the primary and M2 = (89 ± 16) Msun for the secondary component of A1. The primary in A1 is the most massive star weighed so far (Schnurr et al., 2008, MNRAS 389, L38).→ NGC 3603. NGC 404      NGC 404Fr.: NGC 404   A galaxy discovered in 1784 by William Herschel that happens to lie nearly along the line of sight to the star → Beta Andromedae. More specifically, it lies at an angular separation of seven arc-minutes. For this reason it is known also as → Mirach's Ghost. NGC 404 is in fact a → dwarf galaxy lying at a distance of about 10 million → light-years (3.07 ± 0.37 Mpc). NGC 404 harbors a low-luminosity → active galactic nucleus powered by the lowest-mass (< 150,000 Msun) central → massive black hole (Nyland et al., 2017, ApJ 845, 50).NGC, → New General Catalogue. NGC 4993      NGC 4993Fr.: NGC 4993   A → lenticular galaxy (S0) in → Hydra constellation located about 130 million → light-years (40 ± 8 Mpc, → redshift z = 0.009680) from Earth, discovered by William Herschel in 1789. On 17 August 2017 the → Laser Interferometer Gravitational-Wave Observatory (LIGO) and the → Virgo Interferometer both detected → gravitational waves (→ GW170817) from the collision of two → neutron stars within this galaxy. The → electromagnetic counterpart GRB 170817A was detected 1.7 seconds later. The event was associated with a → kilonova offset 10.6 arcsec (corresponding to 2.0 kpc) to north-east from the nucleus of NGC 4993.NGC, → New General Catalog NGC 5866      NGC 5866Fr.: NGC 5866   A → lenticular galaxy in the constellation of the → Draco. It lies about 50 million → light-years (15.3 Mpc) distant and has a size of about 60,000 light-years. Due to its thin → rdge-on appearance, it is also called the → Spindle Galaxy. Known also as Messier 102.5866, a serial number in the → New General Catalogue.