Alpha Coronae Borealis
Alpha Coronae Borealis

Alpha Coronae Borealis is a close binary consisting of a blue-white spectral type A star and a smaller yellowish star somewhat smaller than our own Sun. Like Mizar and Alcor it is a part of the Ursa Major Moving Group. Dust has been detected in its surroundings which suggests that the binary may have a solar system of its own to some extent.

Alpha Bolearis Union System Upward Sector Former Vrill System -

------------------- Eight Proto Planets – One Rock Core Planet -2 Dense Matter Discs The System was the site of an intense Battle against the Vrill,(United Earth /Vrill) with the Vrill winning the battle. But the Vrill unwilling to press their advantage against their children, seceded the system to United Earth. The Rock Core Planet is named after Auria Soltis a Vrill Battle Commander. The Matter Discs are scooped. There is a Gigamon Space Station processing the Scoop and a separate Refinery. The Station is called Bolearis Gold


It has the traditional names Alphecca (Alphekka), Gemma, Gnosia (Gnosia Stella Coronae), and Asteroth (Ashtaroth). The name Alphecca is Arabic, short for نير الفكّة nayyir al-fakka "the bright (star) of the broken (ring of stars)". Gemma is Latin for "jewel". Gnosia is also Latin, short for Gnōsia stella corōnæ "star of the crown of Knossos". Asteroth is Hebrew, עשתרות ‘ašterôt "Astarte (idols)". As the brightest star in Corona Borealis, it lent its name to the brightest in Corona Australis, Alphekka Meridiana.

The term nayyir al-fakka or Nir al Feccah was appeared in Al Achsasi Al Mouakket catalogue.[10]

In Chinese, 貫索 (Guàn Suǒ), meaning Coiled Thong, refers to an asterism consisting of α Coronae Borealis, π Coronae Borealis, θ Coronae Borealis, β Coronae Borealis, γ Coronae Borealis, δ Coronae Borealis, ε Coronae Borealis, ι Coronae Borealis and ρ Coronae Borealis.[11] Consequently, α Coronae Borealis itself is known as 貫索四 (Guàn Suǒ sì, English: the Fourth Star of Coiled Thong.).[12]

Alpha Coronae Borealis (α CrB, α Coronae Borealis) is a binary star in the constellation Corona Borealis. It is located about 75 light years from the Solar System.

[edit] PropertiesThe primary component is a white main sequence star that has a stellar classification of A0V and 2.6 times the mass of the Sun. Estimates of the star's radius range from 2.89 to 3.04 times the radius of the Sun.[2][5] An excess of infrared radiation at 24 μm and 70 μm has been detected about the primary star by the IRAS.[7] This suggests the presence of a large disc of dust and material around Alphecca, prompting speculation of a planetary or proto-planetary system similar to that currently assumed around Vega.

The secondary component is a yellow main sequence star with an estimated stellar class of G5, 0.92 times the Sun's mass and 0.90 times the Sun's radius. The X-ray luminosity of this star is 6 × 1028 erg s-1, which is 30 times greater than the peak activity level of the Sun. This higher activity level is expected for a young star of this class. The corona has a temperature of about 5 MK, which is much hotter than the Sun's corona. The upper limit of 14 km/s for the equatorial rotation velocity is equivalent to a rotation period of 3 days. More likely, the rotation period is 7–9 days.[2][5]

The stars are orbiting about each other in an eccentric orbit one every 17.36 days. Because the plane of this orbit is inclined at an angle of 88.2° to the line of sight to the Earth,[5] the pair form an eclipsing binary system similar to Algol (β Per). The periodic eclipses result in a magnitude variation of +2.21 to +2.32,[8] which is hardly noticeable to the unaided eye.

The space velocity components of this star system are U = +14.257, V = +0.915 and W = +3.147 km/s. α CrB is believed to be a member of the Ursa Major Moving Group of stars that have a common motion through space.[9]

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