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}} Delta Scorpii (δ Sco, δ Scorpii) is a star in the constellation Scorpius. It has the traditional name Dschubba or Dzuba, from Arabic ''jabhat'', "forehead" (of the scorpion); also Iclarcrau or Iclarkrav. Because Delta Scorpii is near the ecliptic it is occasionally occulted by the Moon, or (extremely rarely) by planets. Delta Scorpii is a proper motion member of the Upper Scorpius subgroup of the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.〔 The Upper Scorpius subgroup contains thousands of young stars with mean age 11 million years at average distance of 470 light years (145 parsecs).〔 A recent analysis〔 of the HR diagram position for Delta Scorpii estimates its effective temperature to be 27,400 K with a luminosity of 38,000 times that of the Sun, consistent with an isochronal age of 9–10 million years and an estimated mass of 14.6–14.9 solar masses. ==System== Dschubba is a binary star. The primary is a B class subgiant surrounded by a disc of material spun off by the rapidly rotating star. The secondary orbits every 10.5 years in a highly elongated elliptical orbit. The secondary appears to be normal B class main sequence star. There have been reports that Delta Scorpii A is itself a very close spectroscopic binary, but this does not appear to be the case. The presence of a third star in the system is still being debated.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Delta Scorpii」の詳細全文を読む スポンサード リンク
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