Bootes constellation. Star Arcturus in the constellation of Bootes, the herdsman. Bootes is a large spring and summer constellation for observers in the northern hemisphere. It lies between Ursa Major and Virgo and contains the fourth brightest star in the sky, Arcturus (at centre). Arcturus is a normal orange star. It is cooler than the sun but is four times heavier, 115 times brighter and has a diameter which is over 20 times as large. Arcturus is moving across the sky, relative to the rest of the constellation, towards Virgo.