Grand Star

"Oh, thank you for saving the red. These star people are my family... They mean so much to me."

- Rosalina

Grand Stars are large and powerful Power Stars in Super Mario Galaxy and Super Mario Galaxy 2. There are seven in the first game and six in the second game for a grand total of thirteen.

In Super Mario Galaxy, Grand Stars are used to provide power to the six domes onboard the Comet Observatory, thereby allowing the player to reach more galaxies as the events of the game progress. In Super Mario Galaxy 2, Grand Stars still allow the player to reach more and more galaxies, but they now provide direct access to the next World via their transformation into a Portal instead.

Super Mario Galaxy
Super Mario Galaxy is the first game in which Grand Stars appear. Bowser has taken all of the Grand Stars and is using them for his own evil intentions. As Mario recovers them, he gradually gains access to different parts of Rosalina's Comet Observatory, as the Grand Stars are the power source of the Comet Observatory's Beacon, which in turn sustains all life onboard the observatory. As each Grand Star is found, a path to the next dome is created. Counting the Grand Star obtained from clearing Bowser's Galaxy Reactor, it is only required to obtain 6 of the 7 Grand Stars to complete the game. The Grand Star from the Engine Room can be completely skipped, as Bowser's Galaxy Reactor can be unlocked as soon as the player clears the previous dome (provided they have 60 Power Stars).

Super Mario Galaxy 2
Grand Stars make another appearance in Super Mario Galaxy 2, the 2010 sequel to Super Mario Galaxy. In this game, the Grand Stars are once again under the control of Bowser and Bowser Jr. This time around, Grand Stars restore power to Starship Mario, and also create the Portals leading from one World to the next. In addition to this, the Grand Stars in this game are apparently responsible for Bowser's huge size, as he has eaten them to make himself considerably larger. After Mario defeats one of Bowser Jr.'s machines or henchmen, it will explode and release a Grand Star. After Mario defeats Bowser, he will cough up a Grand Star. During the final battle in Bowser's Galaxy Generator, he is actually able to swallow the Grand Star again, making himself a great deal larger than he had been, and leading to one final segment of the battle. The Grand Stars seem to have an interesting side effect when misused, one that causes Bowser to become extremely tiny after the final battle, as seen in the end credits of the game.

In Bowser Jr.'s Fiery Flotilla, if Mario asks for the Cosmic Spirit's help, the Grand Star will turn into a Bronze Grand Star; this is the only such bronze star that appears in the entire game.

Mario Kart series
While Grand Stars have not appeared physically throughout the Mario Kart series, they have been consistently used as Rosalina's emblem, and later, Baby Rosalina's as well. In the latter's case, the emblem features a Grand Star inside blue bonnet frills.

Mario Kart 8 / Mario Kart 8 Deluxe
In Mario Kart 8 and Mario Kart 8 Deluxe, a floating Grand Star replaces the star icon that can be seen rotating on top of the tower in the city in.

Mario Kart Tour
Grand Stars appear in Mario Kart Tour as collectibles, earned by attaining a certain score after each race, completing tour challenges, Gold Pass challenges, daily challenges (prior to the Wedding Tour), and by using star tickets. Prior to the Baby Rosalina Tour, to unlock more cups and progress further through each tour, a certain number of Grand Stars was required. In every tour, each tour gift also requires a certain number of Grand Stars to open. From the Baby Rosalina Tour to the Anniversary Tour, Grand Stars also unlocked free pipe launches from the weekly spotlight pipes. When the player has opened every tour gift, any subsequent Grand Stars earned are converted to 100 coins each, and when a new tour begins, the total is reset to zero. Rosalina (Swimwear)'s teal swimdress is also decorated with Grand Stars.

Minecraft
In the Super Mario Mash-up in Minecraft, Nether Stars are replaced by Grand Stars.

Super Smash Bros. Ultimate
Rosalina's Final Smash in Super Smash Bros. Ultimate utilizes a Grand Star, in place of the Power Star from the previous installments.

Appearances as Rosalina's emblem
Rosalina's emblem is a Grand Star throughout many of her other appearances, including Super Mario 3D World, Mario Tennis games, other sports games, the Mario Kart series, and the Mario Party series. In Super Mario 3D World, her emblem can be seen whenever she grabs a Goal Pole or touches a Checkpoint Flag, and on Rosalina's Character Switch. In Mini Mario & Friends: amiibo Challenge, the Grand Star is similarly used to signify Mini Rosalina's levels.

Mario Kart Tour

 * Mario Kart Tour Twitter: Collect Grand Stars by earning points in races or by testing your driving skills in challenges! The more Grand Stars you earn, the more Cups and Tour Gifts you unlock. Try to collect enough Grand Stars to unlock everything in a single tour!

Trivia

 * Bowser Jr.'s Fearsome Fleet is the only galaxy where Yoshi is able to pose with Mario when the Grand Star is collected. In Bowser's Galaxy Generator, Princess Peach, Baby Luma and the Co-Star Luma (if used) will pose with Mario. If Mario also brings Yoshi to the end of the level with a glitch, they will not pose since there is no special animation that Mario and Yoshi have with that Grand Star.