Constraining the Origin and Dynamical Evolution of Extreme Trans-Neptunian Objects through NIR Spectroscopy

We propose to obtain low-resolving power (R~100) near-infrared spectra of 6 extreme trans-Neptunian Objects (ETNOs) using the NIRSpec IFU and the Prism/CLEAR combination to constrain ETNO origins. The ETNOs are a unique and understudied population of trans-Neptunian objects with large perihelia (> 37 au) and semi-major axes (> 150 au) that could not have been placed on their current orbits via Neptune on its current orbit. The majority of the members of this population were only discovered within the past 10 years due to their faintness and no observations of ETNOs were approved in Cycle 1 or 2, representing a large gap in our understanding of the trans-Neptunian region. In this investigation, we will compare the spectra of the 6 ETNO targets to each other to determine if the population is compositionally heterogeneous and therefore formed in different regions of the solar nebula. We will also compare the ETNOs to objects in other TNO sub-populations to constrain their possible origins. The excellent sensitivity of JWST will provide us with an unparalleled opportunity to study these extreme and poorly understood objects as a stepping stone to addressing larger questions about the era of planetary migration, the possible presence of a distant outer planet, and the structure and formation of debris disks around other stars.