Yes, CORONAE is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, R 1, O 1, N 1, A 1, E 1.

Is it a valid word?

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

the outermost region of the sun's atmosphere; visible as a white halo during a solar eclipse
(botany) the trumpet-shaped or cup-shaped outgrowth of the corolla of a daffodil or narcissus flower
an electrical discharge accompanied by ionization of surrounding atmosphere
one or more circles of light seen around a luminous object
(anatomy) any structure that resembles a crown in shape
a long cigar with blunt ends

Also: corona discharge, st. elmo's fire, saint elmo's fire, saint elmo's light, saint ulmo's fire, saint ulmo's light, electric glow.