Ruchbah

Its story

Ruchbah is the white star tracing Cassiopeia's knee, faintly variable, some 99 light-years away. Its name, from the Arabic «rukbah», means precisely that: 'knee'. It belongs to the most recognisable W of the northern sky, that angular stroke which for centuries served both as a navigator's mark and as a guide for anyone wishing to find their bearings on a dark night with no map but the stars.