Dreaming of a celebrity usually isn't about that specific person -- it's more about recognition and the parts of yourself you'd like to see valued more publicly. The dream can reflect aspiration, a quality you admire in them that you're growing into, or discomfort with how much of yourself you show the world. Meeting a celebrity calmly in a dream often points to becoming easier with being seen.
The dominant star being in the Midheaven, exalted or in its domicile and taking part of the ascendant. - Picatrix (Andalusia, ~1000.AD)