Thoron
From superman.nu: Supermanica
A far-distant planet, orbiting in the same solar system that was once occupied by the planet Krypton. The planet has been described as "a smaller world than mighty Krypton—but still much larger than Earth!" Thoron is the home planet of the alien Halk Kar. (S No. 80/1, Jan/Feb 1953: "Superman's Big Brother!")