The brightest star of the constellation (0.85 mag). An orange giant of spectral class K5, its name is of Arabic origin and means "another" - because it appears after the Pleiades and follows them in their daily motion from east to west. It is located 65 light-years away from us and represents the eye of the Bull in the sky. Its actual luminosity reaches 125 times the luminosity of the Sun. It coincidentally appears to be projected onto the open star cluster Hyades, which actually lies beyond it.