An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 466 Search : pH

Fr.: morphisme   

A → mapping between two → objects in a → category.

morphology; → -ism.

From rixt, → morphology, + -mandi, → ism.

rixtšenâxti (#)

Fr.: morphologique   

Of or relating to → morphology. Same as morphological

morphology; → -ic.

rixtšenâxti (#)

Fr.: morphologique   

Of or relating to → morphology. Same as morphological

morphologic; → -al.

morphological classification
  رده‌بندی ِ ریخت‌شناختی   
radebandi-ye rixtšenâxti (#)

Fr.: classification morphologique   

A classification scheme of galaxies based on their apparent shape. → Hubble classification.

morphological; → classification.

  ریخت، ریخت‌شناسی   
rixt, rixtšenâsi (#)

Fr.: morphologie   

1) The study of the form or → structure of anything.
2) The → form and structure of a whole entity under study.
3) Linguistics: The structure of → words in a → language, including patterns of → inflections and → derivation. The study and description of such structures.

From Gk. morphe "form, shape, outward appearance" + → -logy.

Rixt "shape, the way something is cast, as in founding," past stem of rixtan "to cast; to pour; to flow" (Mid.Pers. rēxtan and rēcitan "to flow;" Av. raēk- "to leave, set free; to yield, transfer," infinitive *ricyā; Mod.Pers; rig in morderig "heritage" (literally, "left by the dead"); cf. Skt. rinakti "he leaves," riti- "stream; motion, course;" L. rivus "stream, brook;" Old Church Slavic rēka "river;" Rus. reka "river;" Goth. rinnan "run, flow," rinno "brook;" O.E. ridh "stream." šenâsi, → -logy.

morphology-density relation
  بازانش ِ ریخت-چگالی   
bâzâneš-e rixt-cagâli

Fr.: relation morphologie-densité   

An observationally determined relationship between the → morphological classification of galaxies and the → environments in which they are located. Specifically, the morphology-density relation indicates that early-type galaxies (→ ETG) are preferentially located in high density environments, whereas late-type galaxies (→ LTG) are preferentially found in low density environments. Hence, spiral galaxies are rare in the high densities of clusters and are common in the lower density group environments. Early-type galaxies, on the other hand, are common in clusters and are rarely found in isolation.

morphology; → density; → relation.

Mu Cephei
μ Kefeus

Fr.: μ Cephei   

A → red supergiant star in the → constellation → Cepheus. It is one of the largest and most luminous stars known in the → Milky Way. μ Cephei appears garnet red and is given the → spectral type of M2 Ia. The star may even be the largest star visible to the → naked eye with an estimated radius of 1.15 billion kilometres. If it replaced the Sun, it would extend beyond the orbit of Saturn. Some of its → physical parameters are: mass = 15 Msol; → radius = 1650 Rsol; → luminosity = 60 x 104 Lsol; → effective temperature = 3690 K. Also called Herschel's → Garnet star.

Cephei, genitive of → Cepheus.

narrow-band photometry
  شیدسنجی ِ باریک‌باند   
šidsanji-ye bârik bând

Fr.: photométrie à bande étroite   

Photometry using narrow-band filters to isolate a particular spectroscopic line or molecular band.

narrow band; → photometry.

abršenâsi (#)

Fr.: néphologie   

The branch of meteorology that deals with clouds.

From Gk. nephos "cloud," nephele "cloud;" cognate with Pers. nam "moisture;" Av. napta- "moist," nabās-cā- "cloud," nabah- "sky;" L. nebula "mist," nimbus "rainstorm, rain cloud;" Skt. nábhas- "moisture, cloud, mist;" O.H.G. nebul; Ger. Nebel "fog;" O.E. nifol "dark;" PIE base *nebh- "cloud, vapor, fog, moist, sky" + → -logy.

Abršenâsi, from abr "cloud," from Mid.Pers. awr, abr (Laki owr, Baluchi haur, Kurd. Soriani hewr); Av. awra- "rain cloud, rain;" cf. Skt. abhra-"thunder cloud;" Gk. afros "scum, foam;" L. imber "rain;" also Sk. ambha- "water;" Gk. ombros "rain," PIE *mbhros "rain cloud, rain," from *mbh- + -šenâsi-logy.

Newton-Raphson method
  روش ِ نیوتن-رفسون   
raveš-e Newton-Raphson

Fr.: méthode de Newton-Raphson   

A method for finding roots of a → polynomial that makes explicit use of the → derivative of the function. It uses → iteration to continually improve the accuracy of the estimated root. If f(x) has a → simple root near xn then a closer estimate to the root is xn + 1 where xn + 1 = xn - f(xn)/f'(xn). The iteration begins with an initial estimate of the root, x0, and continues to find x1, x2, . . . until a suitably accurate estimate of the position of the root is obtained. Also called → Newton's method.

Newton found the method in 1671, but it was not actually published until 1736; Joseph Raphson (1648-1715), English mathematician, independently published the method in 1690.

northern hemisphere
  نیم‌سپهر ِ هودری   
nimsepehr-e hudari

Fr.: hémisphère nord   

The half of the → Earth or another → astronomical object between the → north pole and the → equator.

northern; → hemisphere.

nuclear physics
  فیزیک ِ هسته‌ای   
fizik-e haste-yi

Fr.: physique nucléaire   

The branch of physics which is concerned with the study of atomic nuclei, subatomic particles, and their exploitation.

nuclear; → physics.

oblate spheroid
  کره‌وار ِ پخ   
korevâr-e pax

Fr.: sphéroïde aplati   

An ellipsoid produced by rotating an ellipse through 360° about its minor axis. Compare with → prolate spheroid.

oblate; → spheroid.

oblique sphere
  سپهر ِ یکور   
sepehr-e yekvar

Fr.: sphère oblique   

The celestial sphere when the circles parallel to the equator are cut obliquely by the horizon plane, which divides them into two unequal parts. In other words, the sphere when its axis is oblique to the horizon of the place.

oblique; → sphere.

observational astrophysics
  اخترفیزیک ِ نپاهشی   
axtarfizik-e nepâheši

Fr.: astrophysique observationnelle   

That part of astrophysics that is mainly concerned with the collection of observational data, in comparison with theoretical astrophysics

observational; → astrophysics.

oqyânus-šenâsi (#)

Fr.: océanographie   

The study of the ocean, embracing and integrating all knowledge pertaining to the ocean's physical boundaries, the chemistry and physics of sea water, and marine biology.

ocean + → -graphy.

Oqyânusocean + -šenâsi-logy.

  ا ُفلیا   
Ofeliyâ (#)

Fr.: Ophélie   

A small satellite of → Uranus, the second nearest to the planet, discovered from the images taken by the Voyager 2 spacecraft in 1986. Also denoted Uranus II, it has a diameter of 32 km. Ophelia is one of the two → shepherd moons that keep the planet's Epsilon ring, the other being → Cordelia.

Ophelia is the daughter of Polonius in Shakespeare's Hamlet.

Mâr-afsâ (#)

Fr.: Ophiuchus   

The Serpent Holder. An extensive constellation located in the equatorial regions of the sky at about 17h 20m right ascension, 5° south declination. Although this constellation is not part of the zodiac, the Sun passes through it in December each year. Ophiuchus contains five stars of second magnitude and seven of third magnitude. Other designations: Serpent Bearer, Serpentarius. Abbreviation: Oph, genitive: Ophiuchi.

L. Ophiuchus, from Gk. ophioukhos "holding a serpent," from ophis "serpent" + echein "to hold, have, keep." The most recent interpretation is that the figure represents the great healer Asclepius, a son of the god Apollo, who learned the secrets of keeping death at bay after observing one serpent bringing another healing herbs. To prevent the entire human race from becoming immortal under Asclepius' care, Zeus killed him with a bolt of lightning, but later placed his image in the heavens to honor his good works.

Mâr-afsâ "a tamer or charmer of serpents; one who cures the snake-bitten by incantation," from mâr "snake, serpent" (Mid.Pers. mâr "snake;" Av. mairya- "snake, serpent") + afsâ agent noun of afsâyidan, from afsun "incantation" (Mid.Pers. afsôn "spell, incantation," afsûdan, afsây- "to enchant, protect by spell").

orbital phase
  فاز ِ مداری   
fâz-e madâri

Fr.: phase orbitale   

In → photometry of → binary stars or → two-body systems, the number of whole or fractional orbits completed, from the point the photometry begins. The point is conventionally chosen as the position at which the → primary star eclipses the → secondary star, and therefore the → light curve is at a minimum. The phase keeps counting indefinitely, thus the secondary star gets eclipsed at phase 0, 1, 2, 3, and so on. At these phases the primary lies between the secondary and the observer. An orbital phase of 0.5 corresponds to halfway through the binary orbit, 0.75 is three-quarters the way through, and so on.

orbital; → phase.

orbital phase curve
  خم ِ فاز ِ مداری   
xam-e fâz-e madâri

Fr.: courbe de la phase orbitale   

The photometric variability induced by the → orbital motion in a → two-body system.

orbital; → phase.

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