An Etymological Dictionary of Astronomy and Astrophysics

The fourth brightest star in the sky (V magnitude -0.06) lying in the constellation → Boötes at a distance of about 35 light-years. Arcturus is a red giant of spectral type K2 IIIp.

Etymology (EN): L. Arcturus, from Gk. Arktouros “guardian of the bear,” arktos “bear,” → Arctic + ouros “guardian, watcher”.

Etymology (PE): Xersbân “guardian of the bear,” from xers “bear” (Mid.Pers. xirs, Av. arša-, cognate with Gk. arktos, Skt. rksa, L. ursus; PIE *rtko-) + -bân suffix meaning “watcher, keeper, guard”.
Ar. Semâk-e râmeh.