During the Galactic War, around the beginning of the Revanite crisis, Altair 9 was attacked by the Galactic Republic. Following a ten-month long siege, the planets capital, Klemark, was finally freed from Imperial control. Food and other aid was subsequently provided to the long-suffering people of the planet by the Republic.
Located on the edge of space controlled by the Confederacy of Independent Systems, by the time of the Clone Wars, the planet was involved in a small skirmish between the Republic and the Separatists. Fighting on the ground, ARC Trooper Alpha-98 was attacked by a broca whilst fighting against the Separatist Droid Army.
Altair is the name of a well-known star in Earth's own Galaxy, and the use of this name in Star Wars can be compared to the references to Rigel VII; but the use of Arabic rather than Roman numerals in the source, "Altair 9" rather than "Altair IX", suggests that Altair 9 may be the ninth moon of a gas-giant named Altair, rather than the ninth planet of a star of that name.