Gamma Hydra II

From Memory Alpha, the free Star Trek reference

Gamma Hydra II is the second planet in the Gamma Hydra system.

When crewmembers of the USS Enterprise, including Captain Kirk were afflicted by radiation on Gamma Hydra IV, causing them to age rapidly, Kirk several times mistakenly stated that the Enterprise orbited Gamma Hydra II because of the decreased mental capabilities due to his "old age". (TOS: "The Deadly Years")