orbital patterns of trans-Neptunian objects

[notFritzArgelander]

https://phys.org/news/2021-06-orbital-p ... unian.html

[helicon]

Interesting that the objects are classified as grey or red, according to their surface colors. I need to read up more on trans-Neptunian objects to improve my understanding. Thanks notFritz.

[turboscrew]

"...gray and red TNOs have vastly different orbital patterns."
WHAT!?

Ahh, there was some possible explanation in the sudy.

[notFritzArgelander]

"...gray and red TNOs have vastly different orbital patterns."
WHAT!?

Ahh, there was some possible explanation in the sudy.

https://iopscience.iop.org/article/10.3 ... 881/abf6ca

We investigate the origins of the photometrically very red (VR) and less red (LR) trans-Neptunian objects (TNOs). We first reanalyze the data set of Marsset et al. and find that in addition to the known color–inclination correlation in hot TNOs, a similar trend exists for color–eccentricity. We show that VR TNOs are sharply constrained to eccentricities <0.42 and inclinations <21°, leading to a paucity of VR scattered disk and distant mean motion resonance objects. We then interpret these findings using N-body simulations accounting for Neptune's outward migration into a massless particles disk and find that these observations are best reproduced with an LR-to-VR color transition line between ~38 and 42 au in the primordial disk, separating the objects' formation locations. For an initial surface density profile (Σ ∝ 1/r2), a color transition around 38 au is needed to explain the high abundance of VR plutinos, but it creates too many VR scattered disk objects, while a transition line around 42 au seems to better reproduce the scattered disk colors but creates virtually no VR plutinos. Our simulations furthermore show that the rarity of VR particles at high eccentricity is possibly due to the absence of sweeping higher-order MMRs, and secular resonances, beyond 42 au. Inspecting individual populations, we show that the majority of VR SDOs originate as objects trapped in Neptune's second- and third-order MMRs. These then evolve due to diffusion, scattering, Kozai–Lidov cycles, and secular resonances into their current orbits. Future unbiased color surveys are crucial to better constrain the TNOs dynamical origins.

[turboscrew]

Yes. I can understand, if you have a red granite rock here and gray granite rock over there, and you explode them, you can expect the red particles to have different trajectories than gray particles.

I guess the point in the article is that the different-colored TNOs are from different origin.

[notFritzArgelander]

Yes. I can understand, if you have a red granite rock here and gray granite rock over there, and you explode them, you can expect the red particles to have different trajectories than gray particles.

I guess the point in the article is that the different-colored TNOs are from different origin.

Exactly so. In this case the difference in color indicates a difference in origin within the protosolar disk.

[GCoyote]

Red caused by tholins on the surface?

[notFritzArgelander]

Yes, indeed. The presence or absence of thorns is the reason for red or grey objects and comes back to place of origin.