ἄστρων κάτοιδα νυκτέρων ὁμήγυριν,
καὶ τοὺς φέροντας χεῖμα καὶ θέρος βροτοῖς
λαμπροὺς δυνάστας, ἐμπρέποντας αἰθέρι
[ἀστέρας, ὅταν φθίνωσιν, ἀντολάς τε τῶν].
Looking at syntax alone, ignoring all the sorts of things that classics scholars focus on in poetry and drama, rejecting conjectural emendation and leaving the text as it stands, κάτοιδα looks like the main verb, ὁμήγυριν an object of κάτοιδα and ἄστρων νυκτέρων limit ὁμήγυριν. τοὺς φέροντας looks like a second object of κάτοιδα but ἀστέρας might be a delayed second object with several modifiers stacked in front of it.
ἀστέρας
I’m leaning toward the first suggestion that τοὺς φέροντας is a second object of κάτοιδα. At the moment, It seems to present the fewest difficulties.φέροντας χεῖμα καὶ θέρος βροτοῖς
λαμπροὺς δυνάστας
ἐμπρέποντας αἰθέρι