2014 ST373

Lore & Background

2014 ST373 orbits the Sun at a distance of 50.2–158.9 AU once every 1069 years, with a 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. As of February 2020, it has the 8th highest perihelion of all known minor planets. Based on its perihelion of 50.2 AU, it is not a member of the scattered disc population, as those objects typically have perihelia of less than 38 AU and are gravitationally disturbed by Neptune; 2014 ST373's orbit has never brought it close enough to Neptune to be disturbed. It is also not an extreme trans-Neptunian object, as those generally have higher perihelia and/or higher eccentricities. Instead, it occupies a virtually unpopulated region at a perihelion of 50 AU and an eccentricity of 0.5.

The Kozai mechanism is capable of transferring orbital eccentricity to a higher inclination, and it can be speculated that this dynamical phenomenon affected the orbit of 2014 ST373. If so, and if the object had once belonged to the extreme detached disc objects (with eccentricities above 0.8 and semi-major axes of at least 250 AU), the Kozai effect would have slowly decreased its 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.

Based on an absolute magnitude of 5.4 and an assumed albedo of 0.09, its diameter is approximately 370 kilometers. The body's color, rotation period, pole, and shape remain unknown.

Reader's Guide

2014 ST373 is significant as a detached object that occupies a sparsely populated region of the outer Solar System, with a perihelion of 50.2 AU that places it among the top 10 minor planets with the highest known perihelia. Its orbit, with a semi-major axis of 104.53 AU and eccentricity of 0.52, has never brought it close enough to Neptune to be gravitationally disturbed, distinguishing it from scattered disc objects. It is also not classified as an extreme trans-Neptunian object, as those typically have higher perihelia or eccentricities. The Kozai mechanism is speculated to have influenced its orbit, potentially reducing its aphelion from over 450 AU to 159 AU while increasing its inclination, linking it to the same group as 2004 XR190. Its legacy lies in helping to define the boundaries between different TNO populations and in illustrating the dynamical processes that shape the outer Solar System. The object was first observed in 2014 using the Dark Energy Camera at Cerro Tololo Inter-American Observatory, and its physical characteristics beyond diameter remain unknown.

Did You Know?

• 2014 ST373 has the 8th highest perihelion of all known minor planets as of February 2020.
• It is speculated that the Kozai mechanism may have decreased its aphelion from over 450 AU to 159 AU.