According to Stella, Lumens are peaceful creatures of pure light that live inside the stars. In every star/planet, there is a village of Lumens. They are said to never leave their stars, unless they have very serious reasons to. Under Valtor's evil spell, they are changed into Staryummies.
Lumens are the size of a baby with fair skin with different hairstyles, a pair of glowing eyes with star-shaped highlights, and cheeks with pink blushes. They wear dresses. They have a hairband and sparkly, star/five-petal flower-shaped accessories on their hair. Hair styles, colors of their hair, hairbands and dresses and accessories (if have any) are varied.