Arcturus (α Boo / α Boötis / Alpha Boötis) (IPA: /ɑrkˈtjʊərəs/) is the brightest star in the constellation Boötes, and the third brightest star in the night sky, with a visual magnitude of −0.05, after Sirius and Canopus, although it is fainter than the combined light of the two main components of Alpha Centauri, which are too close together for the eye to resolve as separate sources of light, making Arcturus appear to be the fourth brightest. It is the second brightest star visible from northern latitudes and the brightest star in the northern celestial hemisphere. The star is in the Local Interstellar Cloud.
An easy way to find Arcturus is to follow the arc of the handle of the Big Dipper. By continuing in this path, one can find Spica (α Virginis) as well — hence the maxim, "Arc to Arcturus, then speed on to Spica."
