Gamma rays were high energy electromagnetic waves. Sensors for detecting these waves were used onboard Droid tri-fighters.
- Tales of the Jedi: The Sith War 4: Jedi Holocaust
- MedStar I: Battle Surgeons (Mentioned only)
- "And Leebo Makes Three"—Star Wars Insider 128 (Mentioned only)
- Champions of the Force (First appearance)
- Children of the Jedi (Mentioned only)
- Gamma ray on Wikipedia