Shadow Number One was the designation of a hole made in the solar wind of the Unknown Regions' Rapacc system by one of its two gas giant planets. In 19 BBY, the Chiss Senior Captain Mitth'raw'nuruodo, core name "Thrawn," undertook a mission to the system, hoping to have his warship, the Chiss heavy cruiser Springhawk, enter it undetected. As a result, he had it enter through Shadow Number One alongside Admiral Ar'alani's vessel Vigilant, in the visual shadow of the larger ship. Upon entering the system, the Vigilant subsequently exited through another hole, Shadow Number Two, leaving Thrawn to continue on his mission.
Shadow Number One appeared in the 2020 novel Thrawn Ascendancy: Chaos Rising, the first installment of Timothy Zahn's Star Wars: The Ascendancy Trilogy.
Shadow Number One appeared in the 2020 novel Thrawn Ascendancy: Chaos Rising, the first installment of Timothy Zahn's Star Wars: The Ascendancy Trilogy.