Jedi beacon

The Jedi beacon was a communication system used by the Jedi Order. It allowed the Jedi Council to near-instantaneously contact all Jedi throughout the galaxy, without relying on the HoloNet. The Council could program a mass signal broadcast, or a single message to one ship. It was housed in the central security station in the Jedi Temple. In addition to the Temple's computer, each ship carried a small computer capable of sending out messages to other Jedi in the field. One possible message was Return-to-Coruscant, an audio signal consisting of a series of accelerating beeps. It was intended to signal the end of the Clone Wars and order all Jedi in the galaxy to return to the Temple.

During Operation: Knightfall, Darth Vader stormed the Archives and murdered Chief Librarian Jocasta Nu when she refused to grant him access to the beacon, before ordering a number of clone assassins to guard it. He then proceeded to broadcast the Return-to-Coruscant code to any Jedi who had survived Order 66 with the intention of luring them back to the Temple unaware of what had happened, where they would be murdered by the clones stationed at the Temple, some of whom were dressed in Jedi robes. Realizing what was happening to the Jedi, Senator Bail Organa stole the beacon from recently deceased Master Saesee Tiin's ship, the Sharp Spiral and managed to contact Master Obi-Wan Kenobi. Meeting with Grand Master Yoda aboard the Sundered Heart, the two Jedi agreed to infiltrate the Temple and deactivate the beacon in order to prevent any survivors from stumbling into the trap.

After securing the security station, Kenobi altered the beacon to instead warn all surviving Jedi to flee into hiding. Since the changes to the beacon's mechanism were not visible, Kenobi believed that it would take the clone troopers a long time to detect the recalibration and even longer to reset it.

Text and facts from the “Jedi beacon/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.