Lostar (pronounced Lost-Star) was a world in the Unknown Regions, possibly in the S'Ueto Region. It was Finir'Uno's capital. The world passed out of knowledge after Finir's death. It was kept secret by its guardians, notably Captain Vossuk.
It was re-discovered in 40 ABY by Mara Jade and Luke Skywalker. They were almost forced to join their empire, however they were able escape. They told no one of what they found there.