Jedi beacon

The Jedi beacon was a device housed within the Jedi Temple's central security station that served as a means of contact for all Jedi throughout the galaxy. Its typical purpose was to be programmed with a signal that could alert all Jedi to return home to Coruscant. In its simplest form, it consisted of a basic alert signal that was a steady pinging noise. There were also other components, which could send detailed text and holographic messages.

During a youngling lesson at the Jedi temple, Caleb Dume wondered if it could also be programmed to warn Jedi away from Coruscant. Though some were shocked by this, Obi-Wan Kenobi agreed that there could be unexpected reasons why such a message would be necessary.

As part of the siege of the Jedi Temple, Darth Vader activated the beacon to recall the Jedi to Coruscant. The idea behind this was to lure any Jedi who survived Order 66 to the Temple, unaware of the true circumstances, where they would be murdered by the troopers stationed there. Kenobi, however, altered the transmission to a holographic recording of himself to warn all remaining Jedi to keep away. At least two Jedi, Caleb Dume and Cere Junda, received Kenobi's broadcast. Caleb was in hyperspace on the way back to Coruscant and was thus warned to not land on the planet. Junda received it and uploaded the transmission to a holocron.