Starbit Festival is also known as Star Festival. Starbit Festival is an event in Super Mario Galaxy and Super Mario Galaxy 2. Every hundred years a huge comet appears in the skies and sends shooting stars to the ground. Toads gather the stars and form a Power Star.
Prior to Super Mario Galaxy
Starbit Festival is an event that is celebrated every hundred years. Every century, a large comet appears in the skies above the Mushroom Kingdom. The comet sends shooting stars to the ground. Toads gather the stars and brought them to the castle; the stars become a Power Star.
Super Mario Galaxy
Peach sent a letter to Mario to invite him to the Starbit Festival. Toads greeted Mario as he walked in the Mushroom Kingdom. Close to Peach's castle, Bowser's troop interrupted the festival and took Peach and her castle.
Rosalina requested Mario to gather the Power Stars and Grand Stars in order to rescue Peach. Mario freed Peach from Bowser and Bowser Jr.; then a cataclysm occurred. Lumas sacrificed themselves to stop the cataclysm while Rosalina rescued Mario. Rosalina brought Mario back to the Mushroom Kingdom and the Mushroom Kingdom citizens and Koopa Kingdom inhabitants celebrated the Starbit Festival.
Super Mario Galaxy 2
Super Mario Galaxy 2 is another story that also starts with stardust. Peach invited Mario to the Starbit Festival. As Mario headed to the festival, he collected falling Star Bits. Then Mario found an unconscious Luna on the ground. Luma looked confused but joined forces with Mario, allowing Mario to break crystals. Mario freed another Luma, trapped in the crystal. Strangely, as Mario went further, he witnessed Bowser kidnapping Peach. Mario ran to the two Lumas. The three Lumas settled down and one of the Lumas transformed into a Shooting Star to allow Mario to rescue Peach.