Yes, HELIAC is a Scrabble word!

Letter values in Scrabble US: H 4, E 1, L 1, I 1, A 1, C 3.

Is it a valid word?

HELIAC is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

pertaining to or near the sun; especially the first rising of a star after and last setting before its invisibility owing to its conjunction with the sun