Celestia Forums

How can I make a planet orbit a stellar barycenter (DP Leo to be more specific)? Please help!

If you have the barycentre defined in the .stc file, then you'll see it has a name.

DP Leo A is told to orbit DP Leo
DP Leo B is told to orbit DP Leo

<--- that's the barycentre's name.

In the .ssc file, just define the planet as orbiting around that barycentre.



This will make a planet b in orbit of the DP Leo barycentre.

Unless they've fixed it by now, the temperature of the planet will always be 0 K, since it is not orbiting a star anymore. This comes from a limitation where Celestia does not incorporate the heating from stars that the planet is not orbiting (as defined by the .ssc file, the planet is not orbiting any stars, but a barycentre).

Note that the DP Leo system is incorporated in the latest version of extrasolar.ssc/extrasolar.stc which can be downloaded from the Subversion repository. Here's a link to the data directory of the repository.

Hungry4info wrote:Unless they've fixed it by now, the temperature of the planet will always be 0 K, since it is not orbiting a star anymore. This comes from a limitation where Celestia does not incorporate the heating from stars that the planet is not orbiting (as defined by the .ssc file, the planet is not orbiting any stars, but a barycentre).

It is "fixed" in the latest SVN versions by removing temperature display for planets. There were several issues with the numbers that were being displayed, as a result it was decided it was better not to display anything.

Thanks! I just realized I had simply forgotten to close my bracket in the ssc file.

ajtribick wrote:It is "fixed" in the latest SVN versions by removing temperature display for planets. There were several issues with the numbers that were being displayed, as a result it was decided it was better not to display anything.

Ehh fudge. Now I'm going to actually have to do math to find out if a planet is in the habitable zone or not.

Hungry4info wrote:

ajtribick wrote:It is "fixed" in the latest SVN versions by removing temperature display for planets. There were several issues with the numbers that were being displayed, as a result it was decided it was better not to display anything.

Ehh fudge. Now I'm going to actually have to do math to find out if a planet is in the habitable zone or not.

One thing I've noticed, is that for planets in the habitable zone, the apparent magnitude of the parent star is almost always around -26.6 to -26.9. So that should be helpful in determining habitable zones.

EDIT: Actually, I found two online calculators that can help you. The first is an archived version of that "Plan a planet orbiting a main sequence star" page:

http://web.archive.org/web/200111182136 ... eqstar.htm

The other is a stellar luminosity calculator:

http://www.calctool.org/CALC/phys/astro ... _magnitude

Using these together may be quite useful.

A general rule of thumb is for a planet orbiting a close binary, assume that the star is twice as massive and twice as bright as the original.