Rator III
Rator III was an inhabited planet in the Rator system of the Beta Quadrant. This system was located on the Federation side of the Romulan Neutral Zone.

In 2269, a Vendorian posing as Captain James T. Kirk ordered the  on a direct course to Rator III, at the request of Carter Winston, who urged the survival of the planet's entire population was dependent on the Enterprises soonest possible arrival. According to the impostor Kirk, this course was the shortest route to the planet; however, the Enterprise would be traveling through the Romulan Neutral Zone. 

In reality,  was the previous identity of the Vendorian, who was working as part of a Romulan plot to seize the Enterprise. ()

Appendices

Background information 

This planet's quadrant of origin is inferred based on the position of its star system as seen in the star chart appearing in the  episode .

Apocrypha 
In Star Trek Online, a new capital planet for the Romulan Star Empire was established on Rator III following Romulus' destruction in 2387.

External link 
 

de: Rator III
Rator 03
Romulan Neutral Zone