Closer to the galactic rim than Helska is Belkadan, which fell to the Yuuzhan Vong not long ago

Helska is a misserable lump of ice that can barely qualify as a planet. The Goa'uld, for reasons unknown, had seen it fit to deposit a Star Gate on the planet, but hadn't visited it for millenia, no doubt because it had no atmosphere! The orbit is uncluttered but on the planet's surface is a landed Yuuzhan Vong World ship, a giant disk of yorric coral that extends some 300 kilometers across. For several more kilometers is docking areas, surface to space guns, and near the Star Gate, squads of space suited infantry, lumps of yoric coral (used as baracades), and some other unfreindly critters

The planet Helska, was destroyed during an early attempt to invade the Imperial Home Galaxy by shield ships under control of the Imperial Navy and its allies

Dubrillion is the next planet into the galaxy