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: 25 Search : corona
F corona
  تاج ِ F   
tâj-e F

Fr.: couronne F   

The exterior part of the → solar corona, illuminated by solar light scattered or reflected by dust particles. The same phenomenon also produces the → zodiacal light, much farther away from the Sun. The dust particles are at most several microns in size and make up a disk stretching over almost 1 solar radius (700,000 km) from the Sun's surface. Unlike electrons, which are responsible for the → K corona, the dust particles move relatively slowly. Thus, the light scattered by them has the same spectrum as the → photosphere and shows the → Fraunhofer lines. The F corona is the most luminous part of the corona at 1.5 solar radii from the Sun's surface (M.S.: SDE).

F referring to the Fraunhofer lines; → corona.

geocorona
  زمین‌تاج   
zamin-tâj (#)

Fr.: géocouronne   

The outermost part of Earth's atmosphere, a tenuous halo of hydrogen and some helium extending out to perhaps 15 Earth radii, which emits Lyman-alpha radiation when it is bombarded by sunlight.

From → geo- + → corona.

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.

K corona
  تاج ِ K   
tâj-e K

Fr.: couronne K   

The inner part of the → solar corona which extends to about two solar radii. It is due to the → Thomson scattering of light from the → photosphere by the free electrons in the corona. The K corona exhibits a → linearly polarized continuous spectrum. The high speeds of the scattering electrons (on the average 10,000 km s-1 for a temperature of 2 million K) smear out the → Fraunhofer lines except the → H and K lines.

K from Ger. Kontinuum, → continuum; → corona.

solar corona
  هورتاج، تاج ِ خورشیدی   
hurtâj, tâj-e xoršid (#)

Fr.: couronne solaire   

The outermost atmosphere of the Sun immediately above the → chromosphere, which can be seen during a total solar eclipse. It consists of hot (1-2 × 106 K), extremely tenuous gas (about 10-16 g cm-3) extending for millions of kilometer from the Sun's surface.

solar; → corona.

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