Planet in the Pegasus Galaxy, populated by a simple and generally friendly people. It was here that the Genii captured Major Lorne and his team, along with Dr. Lindsay, and burned down a building to fake their deaths.
The residents of 177 were well aware that Genii spies are regularly in their midst.
"177" is almost certainly only a partial designation of the planet, used conversationally by members of the Atlantis expedition. The full designation of the planet is not known.
Coup D'etat - Teyla and Ronon investigate on 177 after Lorne's team is allegedly killed in a fire, and learn that someone has put a bounty on their people.