The Obelisk is a massive 2000 foot high structure built by an unknown alien race who created both a planet and a star. Its origin and purpose are unknown, though it did emit a faint EM field. There were some markings that indicated that an alien language was written over the surface of the Obelisk.
It was discovered by the Destiny expedition, when the Destiny entered the system due to its FTL being temporarily disrupted by the gravitational field of the star. When a shuttle was dispatched to investigate the planet, Lt. Matthew Scott and the crew discovered the Obelisk. It was partly studied, though no hints as to its purpose or origin were uncovered. In the final days of the landing party's stay on the world, a bright light emitted from the top of the Obelisk and the construct emitted a type of unknown radiation. The purpose of this activation was unknown though it was speculated that the device might have sent a signal to its creators. (SGU: "Faith")