Hunt for trojans

[Sapyx]

I may have found a Trojan pair - but the reason I say 'may' is that their orbit lines do not perfectly coincide, although both orbit lines pass through the body of both worlds.
...
So are these truly Trojans, or does the slight difference in orbits suggest that there will be a collision or interaction at some point in the future? Or perhaps gravitational interaction with the Y dwarf planet 7 keeps them apart somehow?

Yes, that's a true trojan pairing. You can have a slight "wobble" and still qualify as being trojan.

The L4 and L5 "trojan" points are stable, in that placing an object in an orbit that is almost, but not quite, at the exact centre of the trojan point is still stable - from the point of view of one planet, the other planet would seem to be wobbling or "orbiting around" the trojan point.

Picture a ball placed on a landscape, with hills and valleys. Put the ball down anywhere, and gravity will make it roll downhill. The L4 and L5 points are the equivalent of placing a ball at the bottom of a crater - it doesn't move, because it can't roll anywhere. But if you place the ball slightly off-centre, but still in the crater, the ball will roll back and forth within the crater, but won't be able to escape it; on a frictionless surface and with no air resistance, it would roll back and forth forever. The L1, L2 and L3 Lagrange points are "unstable" in that they are analogous to balancing a ball on the top of a hill: yes, it's "stable" there in that it won't move if placed exactly on top, but it's "unstable" in that if you give it a slight nudge, off it will roll. This is why in nature (and presumably in ED) you will find L4 and L5 objects (trojans), but not L1/L2/L3 objects.

 

[Sapyx]

And I've just found Jackie Silver's "lost" trojan, while trawling through an old thread that someone just necroed: link to post #52.

The system: Pro Eurl JF-A d88, planets 2 and 3 around star B.
Borrowed pic:

 

[Camulorix]

Updated the sheet and I am going to check out Jackie Silver's system. It's not far away and not yet on EDSM.

 

[Eahlstan]

I just found another trojan:

 

[Eahlstan]

I found another one:

https://imgur.com/gallery/4Km0CIr

 

[Eahlstan]

And another one:

https://imgur.com/gallery/9UO6ATL

 

[Zieman]

Hmm, have to keep an eye open for these.

 

[Eahlstan]

And another one:

https://imgur.com/gallery/SqPd1yi

 

[Spaceman Si]

Just a thought, but hunting trojans might be a lot simpler if there was an orrery available...

 

[malenfant]

I found one, much to my surprise! This one consists of a binary Y Dwarf (+moons) and a big Icy Body, and the object at the L4/L5 point is another big icy body on its own. (Updated with correct pics)

 

[Camulorix]

@Eahlstan: Quite the findings. I would have missed the gas giant trojan in Eord Blao KF-A d1563.

@malenfant: Would be nice if you could post screenshots of scanned bodies, so I could add them to the Google sheet.

 

[malenfant]

@malenfant: Would be nice if you could post screenshots of scanned bodies, so I could add them to the Google sheet.

I've posted the same shots as everyone else (a view of the orbits, and the system map), not really sure what information close up shots would add?

 

[Camulorix]

I've posted the same shots as everyone else (a view of the orbits, and the system map), not really sure what information close up shots would add?

The screenshots are fine but they have one problem: All things are called "unexplored", so I have no idea where you found it.

 

[iain666]

I found one, much to my surprise! This one consists of a binary Y Dwarf (+moons) and a big Icy Body, and the object at the L4/L5 point is another big icy body on its own.

Is that going to be stable long term? Will the fact that one "body" is a binary system going to induce enough of a wobble to shake 6 out of the Lagrangian point over millions of years or does that cancel out over a full orbit?

 

[Camulorix]

Is that going to be stable long term? Will the fact that one "body" is a binary system going to induce enough of a wobble to shake 6 out of the Lagrangian point over millions of years or does that cancel out over a full orbit?

I'm pretty sure that at that distance the barycenter is what matters. But would be interesting to run a few simulations nonetheless.

 

[malenfant]

The screenshots are fine but they have one problem: All things are called "unexplored", so I have no idea where you found it.

Oops! Sorry, I thought I mentioned that! . I've updated the pics in the original post, is that enough info for you?

 

[Camulorix]

Oops! Sorry, I thought I mentioned that! . I've updated the pics in the original post, is that enough info for you?

Yes. It's in the list now.

 

[Orvidius]

Is that going to be stable long term? Will the fact that one "body" is a binary system going to induce enough of a wobble to shake 6 out of the Lagrangian point over millions of years or does that cancel out over a full orbit?

I'm pretty sure that at that distance the barycenter is what matters. But would be interesting to run a few simulations nonetheless.

Sounds right to me (though I'm no expert). The L4 and L5 Lagrange points are the stable ones, with a "bowl" shaped gravity well. As long as the bodies (or their barycenter) don't end up too far away from the Lagrange point due to some other influence, it should be a self-correcting system. Or rather, with real orbital mechanics, it would be. In ED, they're all on rails, of course.

 

[malenfant]

Sounds right to me (though I'm no expert). The L4 and L5 Lagrange points are the stable ones, with a "bowl" shaped gravity well. As long as the bodies (or their barycenter) don't end up too far away from the Lagrange point due to some other influence, it should be a self-correcting system. Or rather, with real orbital mechanics, it would be. In ED, they're all on rails, of course.

On the scale of the orbits, the binary would probably treated as the equivalent of a single object (with a mass equal to the mass of both bodies) located at the barycentre of the binary system. The binary is the 'main body' here as well, the solo icy body is the one that is in the L4/L5 point relative to that.

 

[Orvidius]

The binary is the 'main body' here as well, the solo icy body is the one that is in the L4/L5 point relative to that.

Ah, I didn't realize the binary was the main body here. That's what I get for skimming along! It shouldn't change anything at all, since as you said, the barycenter is really what matters once you get a good distance away.