Unorthodox orbital configurations.

[DraQ]

One of the things that would be nice in Pioneer, would be some more interesting orbital configurations occurring from time to time.

First thing we can have IRL but apparently not in Pioneer is La Grange points.
Picture a system consisting of a body orbiting a more massive one.
In such system there are several points where an even less massive object could remain stationary relative to both objects.
The most obvious position is between two bodies, one of the less obvious ones is beyond the less massive body, just outside its orbit.
Most of those points are unstable, but two of the less intuitive ones aren't - I'm speaking of L4 and L5, which are located on the same orbit as the less massive body, but 60 degrees ahead and behind it.

A body in such point will happy co-orbit as long as its mass is low enough. In case of something like gas giant "low enough" may still translate to an earth-like planet - anyone playing Frontier might remember such configuration in Eta Cassiopeia. A point not occupied by any major body (and this includes unstable points as well) may still be a decent place to build a massive space station.
In our solar system we don't have anything spectacular in L points of planets - just some dust and asteroids, but apparently we do have small moons in L points of some larger ones in satellite system of Saturn, so not only is it theoretically possible, but it already happens on our very doorstep.

Hell, current consensus on the origin of our moon is that we had a companion planet in one of our L points that has grown too large to co-orbit in an orderly manner and slammed into Earth.

Another unorthodox configuration would be planetary binary with a pair of planet orbiting their common barycenter on their way around their sun(s). With life bearing planets or gas giants it could look pretty spectacular, especially if they formed a near contact binary. We do have binary stars, and binary asteroids - why not planets?

Finally, for distant, but massive moons we might have moons of moons, but those are less likely due to stability problems.

[impaktor]

http://www.smbc-comics.com/comics/20130927.png

That being said, I think NASA/ESA has a sun telescope in one of the L-points for Sun-Earth, and the most famous L-point-system in our solar system are those of Jupiter, with the Trojans being full of debris and asteroids. However, having objects large enough to be spherical "planets" etc. I think seems highly unlikely, however, they are well suited for space stations.

[DraQ]

having objects large enough to be spherical "planets" etc. I think seems highly unlikely

The thing is that with universe as large as Pioneers we can't discount something just because it's unlikely, especially when it would spice the game up considerably just by being accounted for.

O class stars are unlikely.

Hell, terrestrial planets with massive satellites are unlikely, especially when the only case we know (us) seem to be a result of an ex L4/5 impactor (heh) that got big enough to have been a Mars-size world.