Rukbat

Its story

Rukbat takes the Arabic 'rukbah', 'knee', and indeed marks the knee of the archer in Sagittarius, just where the centaur figure braces to draw back the bow. Although it is the alpha of its constellation, it is not the brightest member of Sagittarius: traditional names do not always follow the modern hierarchy of brightness measured in magnitudes. It is a hot blue star some 182 light-years away, its light having crossed space since 1844.