Star Chip

Star Chips are items that appear in Super Mario Galaxy and its sequel, Super Mario Galaxy 2. They always appear in sets of five, obviously representing the five points of a star. When Mario collects all five of the yellow pieces, a Launch Star will appear. There are also blue Star Chips in addition to the regular yellow ones. Blue Star Chips are far less common, though they do prove integral to the successful completion of several levels. When all five are collected, they create a Pull Star. Sometimes, upon completing a set of yellow Star Chips, several Pull Stars will appear in addition to the Launch Star.

Trivia
In the Supermassive Galaxy, there are several platforms toward the middle of the level that are shaped like gigantic Star Chips.