نصف الكرة السماوية الجنوبي

(تم التحويل من Southern Celestial Hemisphere)
A star chart of the entire Southern Sky, centered on the south celestial pole

نصف الكرة السماوية الجنوبي Southern Celestial Hemisphere، أو السماء الجنوبية، هو جزء من المنطقة الفلكية الدوارة في السماء. ويمثل النصف الجنوبي من القبة السماوية.

At any given time, the entire Southern Sky is visible from the geographic South Pole, while less of this hemisphere is visible the further north the observer is located. The northern counterpart is the northern celestial hemisphere.

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الفلك

Earth rotating within the celestial sphere. In this view, the Southern Celestial Hemisphere is below the celestial equator, the middle parallel (in cyan).

In the context of astronomical discussions or writing about celestial mapping, it may also simply then be referred to as the Southern Hemisphere.

For the purpose of celestial mapping, the sky is considered by astronomers as the inside of a sphere divided in two halves by the celestial equator.[حسب من؟] The Southern Sky or Southern Hemisphere is, therefore, that half of the celestial sphere that is south of the celestial equator. Even if this one is the ideal projection of the terrestrial equatorial onto the imaginary celestial sphere, the Northern and Southern celestial hemispheres must not be confused with descriptions of the terrestrial hemispheres of Earth itself.[حسب من؟]


الرصد

ملف:Acta Eruditorum - V astronomia, 1711 – BEIC 13378880.jpg
Early-17th-century representation of the southern celestial hemisphere in a table from Acta Eruditorum, 1713

From the South Pole, in good visibility conditions, the Southern Sky features over 2,000 fixed stars that are easily visible to the naked eye, while about 20,000 to 40,000 with the aided eye.[بحاجة لمصدر][محل شك] In large cities, about 300 to 500 stars can be seen depending on the extent of light and air pollution.[بحاجة لمصدر] The farther north, the fewer are visible to the observer.[بحاجة لمصدر]

The brightest stars are all larger than the Sun.[محل شك] Sirius in the constellation of Canis Major has the brightest apparent magnitude of −1.46; it has a radius twice that of the Sun and is 8.6 light-years away. Canopus and the next fixed star α Centauri, 4.2 light-years away, are also located in the Southern Sky, having declinations around −60°; too close to the south celestial pole for either to be visible from Central Europe.[1]

التاريخ

The Southern Sky was first substantially charted by English astronomer Edmond Halley,[2] and published by him in 1679.[3]

انظر أيضاً

المصادر

  1. ^ David Ellyard, Wil Tirion: The Southern Sky Guide. Cambridge Univ. Press, Cambridge 2009, ISBN 978-0-521-71405-1
  2. ^ "Edmond Halley (1656–1742)". BBC. 2014. Retrieved 2021-07-11.{{cite web}}: CS1 maint: url-status (link)
  3. ^ Kanas, Nick (2012). Star Maps: History, Artistry, and Cartography (2nd ed.). Chickester, UK: Springer. p. 123. ISBN 978-1-4614-0917-5.