2014 ST373(not displayed) is located in the "gap", a poorly understood region.
2014 ST373(not displayed) is located in an virtually unpopulated region (q=50 AU and e=0.5.
2014 ST373 orbits the Sun at a distance of 50.2–158.9 AU once every 1069 years; semi-major axis of 104.53 AU. Its orbit has an eccentricity of 0.52 and an inclination of 43.16° with respect to the ecliptic.[3]
2014 ST373 is a distant minor planet and trans-Neptunian object (TNO) beyond the orbit of Neptune and the Kuiper cliff.[3][4] As of February 2020[update], it has the 8th highest perihelia of all known minor planets. Based on a still sufficiently determined perihelion a of 50.2 AU, it is not a member of the scattered disc population, as these objects are thought to have been ejected from the classical Kuiper belt into their current orbits by gravitational interactions with Neptune (semi-major axis of 30.1 AU), and typically have highly eccentric orbits and perihelia of less than 38 AU. 2014 ST373's orbit, however, has never brought it close enough to Neptune to be gravitational disturbed.
On the other hand, this TNO is not an extreme trans-Neptunian object as these objects generally have higher perihelia and/or higher eccentricities. Instead, it is located in a virtually unpopulated region at a perihelion of 50 AU and an eccentricity of 0.5 (see adjunct images, where the grid crosses at q=50 AU and e=0.5)
The Kozai mechanism is capable of transferring orbital eccentricity to a higher inclination.[7][8] It can be speculated that this dynamical phenomenon also affected the orbit of 2014 ST373. If this was the case, and the object had once belonged to the extreme detached disc objects – which have eccentricities above 0.8 and semi-major axes of at least 250 AU, for a perihelion of 50 AU – the Kozai effect would have slowly decreased 2014 ST373's aphelion from over 450 AU to currently 159 AU while increasing its inclination. 2014 ST373 seems to belong to the same group as 2004 XR190.[citation needed]
Based on an absolute magnitude of 5.4,[1] and an assumed astronomical albedo of 0.9, which is a standard default value adopted for trans-Neptunian objects by Johnston's archive,[9]2014 ST373 measures approximately 370 kilometers (230 miles) in diameter.[6] The body's color, rotation period, pole and shape remain unknown.[3][10]
^Allen, R. L.; Gladman, B.; Kavelaars, J. J.; Petit, J.-M.; Parker, J. W.; Nicholson, P. (March 2006). "Discovery of a Low-Eccentricity, High-Inclination Kuiper Belt Object at 58 AU". The Astrophysical Journal. 640 (1): L83–L86. arXiv:astro-ph/0512430. Bibcode:2006ApJ...640L..83A. doi:10.1086/503098. S2CID15588453. (Discovery paper)
