I'm stuck. Trying to create multiple-star systems, not necessarily binaries...

[Parfocal]

I have tried and tried and tried and am about ready to give up completely. I know I'm missing something, probably simple, somewhere.

It's extremely difficult trying to describe something like a star system without pics, but here goes...

I want a red giant as the "primary" star in a system.  Antares (or even Betelgeuse) would be OK, but I'd prefer to keep it fairly "normal" and have no more than say a 7-solar mass "primary" star.  Then, in close orbit, a very hot, blue star, about 1-solar mass that orbits the primary star in about a month (30 days). Then, somewhere in the "life zone", an Earth-type planet (maybe 3-Earth masses) and I'm thinking somewhere in the 8 AU range (doesn't matter, really, if this is the "life zone" or not; I can work all that out later...maybe). Then, in a highly elliptical orbit outside of the others, I'd like a very hot, blue, about 3-solar mass star that is outside the orbits of the first two stars and the planet.

Basically, a close binary (red giant primary, blue secondary, with a large difference in mass) and an inhabitable planet somewhere next, then a stray wandering type hot star that orbits all of those. Is this possible in Universe Sandbox?

I'm probably getting hung up on which stars I should create as binaries, and which ones I should balance, and which ones I should just "drop into place" and let them auto-orbit. I guess I need more information on why I'm creating binaries and what situations I need "orbiters". Am I supposed to be creating barycenters and then pairing them up (Ctrl-clicking pairs) with the outer star? Is there any documentation anywhere about what these functions do?

And just to keep it simple, everything can just be in the same ecliptic, same inclination, circular orbits for now...unless you want to explain what fudging with those settings do as well...then, by all means! 

If you can help me figure this out, it would be very much appreciated!

[vh]

I just place stars or objects in place and click auto orbit :p
On another note, there needs to be an auto orbit feature to lock the inclination in place because its very annoying to have to fix that every time. If it's possible?

[Dan Dixon]

Turns out, given the way the orbit tools work, the order in which you create your simulation is very important.

You want to basically create the simulation with the biggest stuff first and work your way down.

If you create a planet and add moons, then want to make that orbit a newly placed star you'll mess up the orbits of the moons.

Improving the editing tools is a high priority item for me.

[Darvince]

Hmm, that's interesting that they don't work the same if you create even the separate stars/planets/moons in a different order.