Are there any known low-inclination trans-Neptunian objects? All the trans-Neptunian object's orbits I know are very inclined compared to those of the eight recognized planets, and Centaur's orbits are highly inclined as well.
Are there any known Centaurs and/or trans-Neptunian objects or TNOs whose orbit isn't significantly inclined to the ecliptic or to the invariable plane, but is on about the same plane as the eight main planets?
And to double check, the hypothetical planet Nine also has a high orbital inclination, doesn't it?
Queries to the JPL Small Body Database or the ESA Asteroids Dynamic Site for such bodies return several results.
Some of the bigger ones are:
Centaurs with H &lt; 10 and i &lt; 4°

386968 (2012 BR61), q = 11.7 au, Q = 31.6 au
527328 (2007 TK422), q = 17.0 au, Q = 25.2 au

TNOs with H &lt; 5 and i &lt; 2°

119951 (2002 KX14), q = 37.3 au, Q = 40.9 au
42301 (2001 UR163), q = 36.8 au, Q = 66.4 au
48639 (1995 TL8), q = 39.9 au, Q = 65.0 au