Each player draws a Cosmic Star at the start of the game, which is placed in your home system. The stars are like a combination of alien power/moon/tech.
You use the power of your star as long as you have the indicated number of ships in your system. Like the powers, some are mandatory and some are optional.
Also like the powers, they have a use, which means they are subject to a Cosmic Zap.
Unlike powers, moons, or tech, the star's power can be used by any player that has the proper number of ships in that system.
If there's ever a conflict about who gets to use a star's power, the player with more ships gets to use it and the other player(s) do not. If there is a tie, the system owner wins the tie, and then proceeding clockwise from that player.
Cosmic Stars are like playing with double powers, with some slight variations.
See BoardGameGeek for files:
File 1 and
Expansion by Jack Reda