An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 130 Search : plan
anisoplanatism
  انیزوبیراهی، انیزوبیراهمندی   
anizobirâhi, anizobirâhmandi

Fr.: anisoplanatisme   

In an imaging system, the dependence of its performance on field angle. In other words, the spatial variability of the → point spread function for off-axis sources.

an- + → isoplanatism.

anisoplanicity
  انیزوبیراهیگی   
anizobirâhigi

Fr.: anisoplanicité   

The departure from → isoplanicity.

an-; → isoplanicity.

aplanatic lens
  عدسی ِ نابیراه   
adasi-ye nâbirah

Fr.: lentille aplanétique   

A lens designed so as to minimize both its → spherical aberration and → coma.

aplanatism; → lens.

aplanatic system
  راژمان ِ نابیراه   
râžmân-e nâbirah

Fr.: système aplanétique   

An → optical system that is able to produce an image essentially free from → spherical aberration and → coma. See also the → Abbe sine condition.

aplanatism; → system.

aplanatism
  نابیراهی   
nâbirahi

Fr.: aplanétisme   

Freedom from spherical aberration and coma.

Aplanatism, from aplanatic, from a- "negation prefix" + Gk. plane "wandering," from planasthai "to wander" + -tic adjective-forming suffix.

Nâbirahi, from nâ- "negation prefix" + birah "a devious path; a wanderer, who deviates, errs," + -i noun affix.

born-again planetary nebula
  میغ ِ سیاره‌ای ِ باز‌زاد   
miq-e sayâreyi-ye bâzzâd

Fr.: nébuleuse planétaire recyclée   

A → planetary nebula which is thought to have experienced a → very late thermal pulse (VLTP) when the central star (→ CSPN) was on the → white dwarf cooling track. The VLTP event occurs when the thermonuclear → hydrogen shell burning has built up a → shell of helium with the critical mass to ignite its → fusion into carbon and oxygen (→ helium shell burning). Since the → white dwarf envelope is shallow, the increase of pressure from this last helium shell flash leads to the ejection of newly processed material inside the old planetary nebula, leaving the stellar core intact. As the stellar envelope expands, its → effective temperature decreases and the star goes back to the → asymptotic giant branch (AGB) region in the → H-R diagram. The subsequent stellar evolution is fast and will return the star back to the → Post-AGB track in the H-R diagram: the envelope of the star contracts, its effective temperature and ionizing photon flux increase, and a new fast stellar wind develops (see, e.g. J. A. Toalá et al. 2015, ApJ 799, 67).

born; → again; → planetary; → nebula.

compact planetary nebula B[e] star (cPNB[e])
  ستاره‌یِ B[e]ی ِ میغ ِ سیاره‌ای ِ همپک   
setâre-ye B[e]-ye miq-e sayyâre-yi-ye hampak

Fr.: étoile de nébuleuse planétaire compacte   

A star whose spectrum shows striking similarities to → B[e] stars and is evolving into a → planetary nebula (→ preplanetary nebula).

compact; → planetary; → nebula; → B[e] star.

coplanar forces
  نیروهای ِ هم-هامن   
niruhâ-ye ham-hâmon

Fr.: forces coplanaires   

A system of forces acting on a body that all are in the same plane.

com- + planar adj. from → plane.

dwarf planet
  سیاره‌ی ِ کوتوله   
sayyâre-ye kutulé (#)

Fr.: planète naine   

A new category of → astronomical objects in the → solar system introduced in a resolution by the 26th General Assembly of the → International Astronomical Union (IAU) on August 24, 2006. The characterizing properties are as follows: 1) It is in orbit around the Sun; 2) It has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a → hydrostatic equilibrium (nearly round) shape; 3) It has not "cleared the neighbourhood" around its orbit; and 4) It is not a → satellite of a → planet, or other non-stellar body. The property 3 reclassified → Pluto from a planet to a dwarf planet because it has not cleared the neighborhood of its orbit (the → Kuiper Belt). The largest known dwarf planets are: → Eris, → Pluto, → Ceres, → Makemake, and → 2015 RR245.

dwarf; → planet.

ecliptic plane
  هامن هورپهی   
hâmon-e hurpehi

Fr.: plan de l'écliptique   

The plane of Earth's orbit around the Sun.

ecliptic, → plane.

Ecliptic Plane Input Catalogue (EPIC)
  کاتالوگ ِ درداد ِ هامن ِ هورپهی   
kâtâlog-e dardâdâ-e hâmon-e hurpehi

Fr.: catalogue d'entrée du plan de l'écliptique   

A catalog of fields along the → ecliptic observed by the → K2 mission. The catalog is hosted at the → Mikulski Archive for Space Telescopes (MAST).

ecliptic; → plane; → input; → catalogue.

equator plane
  هامن ِ هموگاری   
hâmon-e hamugâri

Fr.: plan équatorial   

An imaginary plane → perpendicular to the → axis of a → sphere dividing the sphere into two congruent parts.

equator; → plane.

equatorial plane
  هامن ِ هموگاری   
hâmon-e hamugâri

Fr.: plan équatorial   

The plane containing a celestial object's equator.

equatorial; → plane.

exoplanet
  برون‌سیاره   
borun-sayyâreh

Fr.: exoplanète   

Same as → extrasolar planet.

exo- + → planet.

exoplanetary
  برون‌سیاره‌ای   
borun-sayyâre-yi

Fr.: exoplanétaire   

Of, relating to, or resembling an → exoplanet or exoplanets.

exoplanet; → -ary.

exoplanetary system
  راژمان ِ برون‌سیاره‌ای   
râſmân-e borun-sayyâre-yi

Fr.: système exoplanétaire   

A → planetary system consisting of → exoplanets orbiting a star other than Sun.

exoplanetary; → system.

exoplanetary transit
  گذر ِ برون‌سیاره‌ای   
gozar-e borun-sayyâre-yi

Fr.: transit d'exoplanète   

The passage of an → exoplanet across the face its star.

exoplanetary; → transit.

explanation
  اُستاهش   
ostâheš

Fr.: explication   

1) The act or process of explaining.
2) A statement made to clarify something and make it understandable.

Verbal noun of → explain.

extrasolar planet
  سیاره‌ی ِ اُسترخورشیدی   
sayyâre-ye ostarxoršidi

Fr.: planète extrasolaire   

A planet which belongs to a star other than → Sun, and therefore does not belong to our → solar system; same as → exoplanet.

extrasolar; → planet.

focal plane
  هامن ِ کانونی   
hâmon-e kânuni

Fr.: plan focal   

A plane at right angles to the principal axis of a lens or mirror on which the best image is formed.

focal; → plane.

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