In Super Smash Bros. for 3DS/Wii U, when performing Power Star, Rosalina will pull out a Power Star which shoots out smaller stars in all directions. The stars will rebound when they hit a surface. These smaller stars are fairly ineffective and can be avoided, but the larger power star will grow in size over the duration of the move. Rosalina is able to move freely a couple of seconds after activating Power Star; she becomes vulnerable to attacks at that time. At the end of the Final Smash, the large star will explode, inflicting high knockback on any nearby characters. If an opponent is knocked into the large star, they will be trapped in it as it expands, receiving potentially 250% damage, and will be knocked back when it explodes. The Power Star will continue to expand even if Rosalina gets KOed or SD's right after she activates the Final Smash.
In Super Smash Bros. Ultimate, the move is renamed as Grand Star. Unlike its previous iteration, Rosalina will summon a Grand Star rather than a Power Star and the smaller stars will launch players into the main star rather than away from it, making it easier to trap opponents in it.