Technically: the definition of the star cluster you're playing in: the names and locations of all the planets.

Generally, you see the whole cluster (i.e. all planet positions) from the start. The popular add-on ExploreMap changes this so you only see planets in scan range.

The starchart consists of the files:

  • xyplan.dat: planet positions. In Explore Map games, each player has his own xyplanN.dat file.
  • planet.nm: the planet names.

Of course, the term starchart is also applied to the section of a client program where you can browse through the universe, compiled from the above files and usually much more information.

This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.