If the player chooses to create a constellation, they may have up to 16 lines in their design. Celeste will ask the player what they would like to call their constellation. Once the player gives it a name, she will put their design in her charts. She will then tell the player the exact time and date their constellation will be most noticeable from the sky. There is no limit on the amount of the constellations.
When a player visits a friend over Wi-Fi, they will exchange constellations, meaning they will see the other player's constellations in their town, and vice versa.