Mystery Trans-Neptunian Object with unexplained orbit *above the ecliptic* discovered

[SPCTRE]

“I hope everyone has buckled their seatbelts because the outer solar system just got a lot weirder.” That’s what Michele Bannister, an astronomer at Queens University, Belfast tweeted on Monday.

She was referring to the discovery of a TNO or trans-Neptunian object, something which sits beyond Neptune in the outer solar system. This one is 160,000 times fainter than Neptune, which means the icy world could be less than 200 kilometres in diameter. It’s currently above the plane of the solar system and with every passing day, it’s moving upwards – a fact that makes it an oddity.

https://www.newscientist.com/articl...ird-orbit-beyond-neptune-cannot-be-explained/

Although the majority of Centaurs are thought to have originated in the scattered disk, with the high-inclination members coming from the Oort cloud, the origin of the high inclination component of trans-Neptunian objects (TNOs) remains uncertain. We report the discovery of a retrograde TNO, which we nickname "Niku", detected by the Pan-STARRS 1 Outer Solar System Survey. Our numerical integrations show that the orbital dynamics of Niku are very similar to that of 2008 KV42 (Drac), with a half-life of ∼500 Myr. Comparing similar high inclination TNOs and Centaurs (q>10 AU, a<100 AU and i>60∘), we find that these objects exhibit a surprising clustering of ascending node, and occupy a common orbital plane. This orbital configuration has high statistical significance: 3.8-σ. An unknown mechanism is required to explain the observed clustering. This discovery may provide a pathway to investigate a possible reservoir of high-inclination objects.

http://arxiv.org/abs/1608.01808

Essentially, they don't know what is keeping this highly unusual orbit above the ecliptic plane. Fascinating.

Spoiler

(Obligatory)

 

[Asbo Zaprudder]

Gravity keeps the object in orbit. It's more a question of what deflected it into that orbit.

 

[Ronald Held]

Could be dynamic friction after all of the migrations of the giant planets?

 

[Asbo Zaprudder]

It would be my guess (and it's just idle speculation) that Niku and perhaps other Kuiper belt objects were ejected into such orbits around the time of the late heavy bombardment when Neptune got pushed outward by Jupiter and Saturn migrating to a 2:1 orbital resonance. However, I'm not familiar enough with the various models -- Nice, Nice 2, Jumping Jupiter, etc -- to offer any deep insight. It appears that the proposed undiscovered distant ice giant cannot be currently responsible as the New Scientist article reports although I imagine it's possible that it disrupted Kuiper belt objects at the time that it was ejected into its present distant orbit by Saturn and Jupiter.

 

[Crazy Eddie]

I thought it was immediately obvious that this was an extrasolar object in a captured orbit, but maybe that's just me?

 

[publiusr]

Or something Planet Nine had interacted with. One more target for investigation.
I want to learn more about Gna: http://www.centauri-dreams.org/?p=34606