Celestia's Invisible Barycenter

Occasionally in Celestia it is useful to have a completely invisible object that other objects can orbit around. The obvious example is the barycentre of a pair of bodies in mutual orbit - Celestia needs an object positioned at the centre of gravity to "carry" the orbits of the two real bodies, but we don't want to be able to see anything in that position when we view the simulated orbits.

With the advent of Celestia 1.3.0, the "empty object" I created for version 1.2.5 is no longer required - its function has been taken over by Celestia's "invisible" class of objects. As an example of the use of Celestia's "invisible" object, I've adapted my original binary_asteroid.ssc file, replacing the rather clumsy definition necessitated by the "empty" object with the more streamlined definition possible in version 1.3.0. I've also created an alternative, barycentric definition of the Pluto-Charon system, which can be used to replace the Pluto-centred system defined in solarsys.ssc. This new version shows Pluto and Charon orbiting realistically around their mutual centre of gravity.

  • binary_asteroids-130.ssc (1KB, 18Apr03)
  • pluto-charon.ssc (1KB, 18Apr03)
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    The content of this Web page was provided by Grant Hutchison.

    This Web page is maintained by Selden Ball at Wilson Lab.
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