The location of a Federation Medical Collection Station where the Enterprise-D took on dangerous plague specimens in 2365 for use in developing a vaccine.
'aucdet IX is a planet that houses a Federation Medical Collection Station, a secure store of disease samples. It appears in the second-season Next Generation opener The Child.
In 2365 an outbreak of plasma plague strikes the Rachelis system. To help find a cure, the Enterprise-D is fitted with a special containment module and sent to 'aucdet IX to collect specimens of the plague and many other lethal organisms, which are to be carried to Science Station Tango Sierra. The station's medical trustee, Lieutenant Commander Hester Dealt, supervises the transfer.
On the way, one strain begins to grow and threatens to breach containment. The cause is a form of radiation given off by Ian, the child born to Deanna Troi, who is really an alien life form and chooses to leave the ship to save it.