P3W-451
From SGCommand
From the perspective of normal space-time, it will be several years before the world is entirely enveloped by the anomaly. SG-10 reported that any indigenous life that may have been on the planet had recently become extinct, the cause of which is unknown. P3W-451 had one moon.
While attempting to establish contact with SG-10, Earth was briefly linked to the black hole and extreme gravity through the connection began to slow relative time inside the SGC. A shaped charge was placed near the event horizon of the Stargate, causing the connection to cut from P3W-451 and "jump" to another nearby gate. (SG1: "A Matter of Time")
When planning to destroy Apophis' fleet, SG-1 used a Stargate to dial P3W-451 and launched it into the star that Vorash orbited. The black hole absorbed the mass, and caused the star to supernova, destroying Apophis' fleet. (SG1: "Exodus")
When the SGC went into negotiations with the Aschen, the SGC offered them a list of addresses as a sign of good faith. When suspicions arose as to the true nature of the Aschen's relations with the Volians, the list of addresses was altered. The first address was that of the black hole of P3W-451. The other addresses supposedly lead to worse planets. (SG1: "2001")
