Beta Boötis Beta Boötis Beta Boötis (β Boötis, abbreviated Beta Boo, β Boo), also named Nekkar, is 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. In the modern constellation, it marks the head of Boötis the herdsman. Based upon parallax measurements obtained during the Hipparcos mission, this star is approximately from the Sun. At that distance, the magnitude of the star is reduced by 0.06 from extinction caused by intervening gas and dust. "β Boötis" (Latinised to "Beta Boötis") is the star's Bayer designation.
Constellation Chaldean astronomy, probably dates back to prehistory. In 1928, the International Astronomical Union (IAU) formally accepted 88 modern constellations, with contiguous boundaries that together cover the entire celestial sphere. Any given point in a celestial coordinate system lies in one of the modern constellations. Some astronomical naming systems include the constellation where a given celestial object is found to convey its approximate location in the sky. The Flamsteed designation of a star, for example, consists of a number and the genitive form of the constellation name. Other star patterns or groups called asterisms are not constellations per se but are