heliacal

From Ancient Greek ἡλιακός (hēliakós, “of the sun”) +‎ -al. Appears in English first in the 16th century.

• (US) IPA^(key): /hɪˈlaɪ.ə.kəl/

heliacal

1. (rare) Of or relating to the Sun, especially rising and setting with the sun.
2. Of or relating to the rising of a star when it first becomes visible just before sunrise in the eastern sky, having previously been made invisible by sunlight, or the analogous situation of its setting just after sunset.

• achillea