The inclinations of faint TNOs

TL;DR

This paper analyzes the orbital inclinations of faint trans-Neptunian objects, revealing a shift from a classical low-inclination dominance to a predominance of excited objects, impacting our understanding of their dynamical history.

Contribution

It updates the classification of faint TNOs, showing a higher proportion of excited objects compared to earlier studies, based on an expanded dataset.

Findings

Faint TNOs are predominantly excited objects, not classical.

The population of faint TNOs has evolved in our understanding since 2004.

Implications for the dynamical history of the outer Solar System.

Abstract

Bernstein et al. (2004) found that the population of faint (R>26) trans-Neptunian objects (TNOs) known at that time was dominated by "Classical" objects, which have low inclinations (i<5 degrees) and distances 40--45 AU. Since those observations, the number of faint TNOs whose orbits are sufficiently well known to be classified as "Classical" or "Excited" has grown from seven to 39. We analyze the dynamical classifications of faint TNOs known today and find that this population is dominated by Excited objects. We discuss some implications of this result.