Yes, AURORAE is a Scrabble word!

Letter values in Scrabble US: A 1, U 1, R 1, O 1, R 1, A 1, E 1.

Is it a valid word?

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

the first light of day
an atmospheric phenomenon consisting of bands of light caused by charged solar particles following the earth's magnetic lines of force
(Roman mythology) goddess of the dawn; counterpart of Greek Eos

Also: first light, break of day, break of the day.