Nesta was a planet located somewhere in Federation space in the galaxy's Alpha or Beta Quadrants.
History and specifics
Nesta is located somewhat near the rogue planet Anomaly and about four weeks' travel at warp speed from the Academy planet.
In the mid-23rd century, Professor James Atheling established a research station on the planet's surface.
In 2269, the Federation starship USS Enterprise arrived at Nesta to pick up Atheling and transport him to the Academy planet.
En route, a falsified distress signal claimed that, while on the surface of Nesta, Atheling, Spock, Leonard McCoy, Andre Charvat, Sharon Follett, and Rosaly Ybarra became infected by a highly virulent plague. That signal prompted the USS Lysander to intercept the Enterprise. (TOS novel: Planet of Judgment)