relating to heaven or the sky: the empyrean domain where human will and God’s will became as one.

noun (the empyrean)

heaven, in particular the highest part of heaven: the unapproachable splendor of the empyrean.

literary: the visible heavens; the sky: we rose through the polluted air into the clear empyrean above.

[A Room with a View — E. M. Forster]