PX3-989 is a planet in Milky Way galaxy which held a Stargate. At 989, a SGC team found a deactivated android body that they took back to Stargate Command for further investigation. (SG1: "Avalon, Part 1")
Behind the scenes
It is entirely possible that this planet is meant to be Altair, which has the similar designation of P3X-989 and was home to the Altairan Androids. However, as this has not been confirmed, it is assumed to be a different planet for the purposes of this article.