sidereal
/sʌɪˈdɪərɪəl
/adjective
Of or with respect to the distant stars (i.e. the constellations or fixed stars, not the sun or planets).Fixed stars continued to be used as reference points throughout the Middle Ages, and even Copernicus measured positions in a sidereal zodiac beginning from the fixed star Mesartim....
- Slightly brighter today is Alpherg, which is taken as the starting point for the sidereal zodiac.
- In the first sphere across the zodiac we see twelve sidereal animals.
Origin
Mid 17th century: from Latin sidereus (from sidus, sider- 'star') + -al.