Matches in DBpedia 2014 for { ?s ?p Beta Boötis (β Boo, β Boötis) is the Bayer designation for a star in the northern constellation of Boötes. It has an apparent visual magnitude of 3.5, making it one of the brighter members of the constellation. The traditional name Nakkar or Nekkar for this star is based upon the Arabic name for the constellation. This is a mis-transliteration of the Arabic بقّار baqqār "cattle driver", the Arabic letters b and n differing only in the placement of the dot.[citation needed] In the modern constellation, it marks the head of Boötis the herdsman. Based upon parallax measurements, this star is approximately 225 light-years (69 parsecs) from Earth. At that distance, the magnitude of the star is reduced by 0.06 from extinction caused by intervening gas and dust.Nakkar has more than three times the mass of the Sun and greater than 21 times the Sun's radius. (König et al. (2006) give it 3.4 solar masses, while Tetzlaff et al. (2011) list a higher estimated mass of 5.0 ± 1.5 solar masses and Takeda et al. (2008) show it as 3.24 solar masses.) At the estimated age of 240–251 million years, it has evolved into a giant star with a stellar classification of G8 IIIa. The star is radiating around 170–194 times as much luminosity as the Sun from its outer envelope at an effective temperature of 4,932 K. This heat gives it the yellow-hued glow of a G-type star. It has an estimated rotation period of about 200 days and the pole is inclined 28° ± 6° to the line of sight from the Earth.In 1993, the ROSAT satellite was used to observe an X-ray flare on Beta Boötis, which released an estimated 1.7 × 1032 erg. This was the first such observation for a low-activity star of this type. The flare may be explained by an as yet unobserved M-type dwarf companion star.. }
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- Beta_Boötis abstract "Beta Boötis (β Boo, β Boötis) is the Bayer designation for a star in the northern constellation of Boötes. It has an apparent visual magnitude of 3.5, making it one of the brighter members of the constellation. The traditional name Nakkar or Nekkar for this star is based upon the Arabic name for the constellation. This is a mis-transliteration of the Arabic بقّار baqqār "cattle driver", the Arabic letters b and n differing only in the placement of the dot.[citation needed] In the modern constellation, it marks the head of Boötis the herdsman. Based upon parallax measurements, this star is approximately 225 light-years (69 parsecs) from Earth. At that distance, the magnitude of the star is reduced by 0.06 from extinction caused by intervening gas and dust.Nakkar has more than three times the mass of the Sun and greater than 21 times the Sun's radius. (König et al. (2006) give it 3.4 solar masses, while Tetzlaff et al. (2011) list a higher estimated mass of 5.0 ± 1.5 solar masses and Takeda et al. (2008) show it as 3.24 solar masses.) At the estimated age of 240–251 million years, it has evolved into a giant star with a stellar classification of G8 IIIa. The star is radiating around 170–194 times as much luminosity as the Sun from its outer envelope at an effective temperature of 4,932 K. This heat gives it the yellow-hued glow of a G-type star. It has an estimated rotation period of about 200 days and the pole is inclined 28° ± 6° to the line of sight from the Earth.In 1993, the ROSAT satellite was used to observe an X-ray flare on Beta Boötis, which released an estimated 1.7 × 1032 erg. This was the first such observation for a low-activity star of this type. The flare may be explained by an as yet unobserved M-type dwarf companion star.".