Why Glow-in-the-Dark Stars Shine

The story

Quarky sticks glowing stars on the ceiling and watches them shine long after bedtime. During the day, the stars soak up photons and electrons jump up to higher energy steps. When the lights go out, those electrons come back down slowly, letting the light out little by little. That slow leak of stored light is called phosphorescence, and it is why the stars glow for hours.