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: 51 Search : planet
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.

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.

exoplanet
  برون‌سیاره   
borun-sayyâreh

Fr.: exoplanète   

Same as → extrasolar planet.

exo- + → planet.

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.

giant planet
  سیاره‌ی ِ غولپیکر   
sayyâre-ye qulpeykar (#)

Fr.: planète géante   

A planet much more massive than Earth. The solar system has four giant planets: → Jupiter, → Saturn, → Uranus, and → Neptune.

giant; → planet.

inferior planet
  سیاره‌ی ِ زیرین   
sayyâre-ye zirin (#)

Fr.: planète inférieure   

A planet that orbits between the Earth and the Sun. Mercury and Venus are the only two inferior planets in the Solar System.

inferior; → planète.

inner planets
  سیاره‌های ِ درونی   
sayârehâ-ye daruni (#)

Fr.: planètes internes   

The planets Mercury, Venus, Earth and Mars collectively. T hey are also known as the terrestrial planets.

inner; → planet.

interplanetary coronal mass ejections (ICME)
  اشانش ِ اندرسیاره‌ای ِ جرم از تاج   
ešâneš-e andarsayyâreyi-ye jerm az tâj

Fr.: éjection de masse coronale interplanétaire   

An → interplanetary manifestation of a → coronal mass ejection.

interplanetary; → coronal; → mass; → ejection.

interplanetary dust
  غبار ِ اندرسیاره‌ای   
qobâr-e andarsayyâreyi

Fr.: poussière interplanétaire   

Particles of dust in the → interplanetary medium. They are left-overs from the beginning of the solar system or from other sources such as sublimating comets. Their existence was first deduced from observations of → zodiacal light.

interplanetary; → dust.

interplanetary gas
  گاز ِ اندرسیاره‌ای   
gâz-e andarsayyâreyi

Fr.: gaz interplanétaire   

Electrically charged particles of the solar wind and gas liberated from comets within the solar system.

interplanetary; → gas.

interplanetary magnetic field
  میدان ِ مغناتیسی ِ اندرسیاره‌ای   
meydân-e meqnâtisi-ye andarsayyârei

Fr.: champ magnétique interstellaire   

The magnetic field that is carried along with the solar wind and fills the solar system space. It is wound into a spiral structure by the rotation of the Sun. At the Earth's distance from the Sun, it has a strength of about 5 x 10-5 gauss.

interplanetary; → magnetic; → field.

interplanetary matter
  مادّه‌ی ِ اندرسیاره‌ای   
mâdde-ye andarsayyâreyi

Fr.: matière interplanétaire   

Material existing in the space between solar system planets. It includes interplanetary gas and dust.

interplanetary; → matter.

interplanetary medium
  مدیم ِ اندرسیاره‌ای   
madim-e andarsayâre-yi

Fr.: milieu interplanétaire   

The material contained in the → solar system in the space through which the planets travel. It consists of the smaller objects such as → asteroids, → comets, → meteorites and also a general pervading → interplanetary dust. Moreover a → plasma of charged particles streaming outward from the Sun in the form of the → solar wind contributes to the interplanetary medium.

interplanetary; → medium.

interplanetary space
  فضای ِ اندرسیاره‌ای   
fazâ-ye anadrsayyâre-yi

Fr.: espace interplanétaire   

Same as → interplanetary medium.

interplanetary; → space.

intramercurial planet
  سیاره‌ی ِ فروتیری   
sayyâre-ye forutiri

Fr.: planète intramercurienne   

A hypothetical planet, named Vulcan, that once was believed to exist between the Sun and Mercury.

intra-; → Mercury; → planet.

Jovian planet
  سیاره‌ی ِ هرمزی   
sayyâre-ye Hormozi

Fr.: planète jovienne   

A planet that does not have a well-defined → solid  → crust, such as any of the four Solar System outer, gaseous planets: → Jupiter, → Saturn, → Uranus, and → Neptune.

Jovian; → planet.

major planet
  سیاره‌ی ِ مهین   
sayyâre-ye mehin

Fr.: planète majeure   

A name used to describe any planet that is considerably larger and more massive than the Earth, and contains large quantities of hydrogen and helium. Jupiter and Neptune are examples of major planets.

major; → planète.

minor planet
  سیارک   
sayyârak (#)

Fr.: petite planète   

An obsolete name used to describe an → asteroid.

minor; → planet.

multiplanet system
  راژمان ِ بس-سیاره‌ای   
râžmân-e bas-sayâre-yi

Fr.: système multi-planète   

A stellar system with more than one orbiting planet.

multi-; → planet; → system.

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