Arien was the maiden whom the Valar chose from among the Maiar to guide Anar the Fire-golden (the vessel of the Sun), fruit of Laurelin. Her name was derived from the root "as-" seen also in the Quenya "árë" - 'sunlight'.

Before the the Sun and Moon, in the days of the Two Trees, Arien took care of the golden flowers in the gardens of Vána, and watered them with the dew of Laurelin.

Arien was chosen because she wasn't scared of the heat of Laurelin, and was unhurt by it, being a spirit of fire. The eyes of Arien were too bright for even the Eldar to look on.

Leaving Valinor, she gave up the form and raiment which like the Valar she had worn there, and she looked like a naked flame, terrible and splendid.
Encyclopedia entry originally written by Arien