At first blush, the two titles of this page would seem to have nothing to do with each other. The Pleiades are a constellation of fixed stars, and one of the first recognized by Greek authors, namely already in Hesiod (8th or 7th century BCE). Planets, on the other hand, are wandering stars (as opposed to fixed stars like those that make up the Pleiades) and only became important to Greek religion from the 4th century BCE onwards. Angels of the planets are a much later development still, and known largely from the late antique Greek Magical Papyri (PGM).
Nevertheless, by reading a ritual from the PGM together with a passage from the Neoplatonist Proclus, we will find that there is a definite connection between the Pleiades and planetary angels in ancient ritual practice, and this connection relates to early mythological poetry in quite a profound way. First, however, I will discuss the Pleiades and the planetary angels separately; only then passing to their interrelation.
2 The Pleiades in myth, astronomy-astrology, and cult
the Pleiades (lat. Pliades;or poetically, Plēïades), are the daughters Plēïonē (more rarely, Pleionē = lat. Plione)
3 Planetary angels in ritual practice annd philosophy
4 The relation of Pleiades and planetary angels