TNO2024

We present novel observations of $g-r$ and $r-z$ surface colors of 3:2 resonators (plutinos) and TNOs in various other dynamical classes discovered/characterized by the Canada-France Ecliptic Plane Survey and the Alexandersen (2016) survey. Our observing program was designed with the goal of observing a brightness-complete ($m_r<23.25$) sub-sample of plutinos from these two surveys. Currently, we have obtained surface colors of 10 out of the 25 plutinos in this sub-sample (40%) using the IMACS instrument on the Magellan Baade telescope. We compare the $g-r$ and $r-z$ surface colors of the measured plutinos to TNOs in other dynamical classes in this sample and the Colours of the Outer Solar System Origins Survey (Col-OSSOS) sample with previously measured $g-r$ and $r-z$ surface colors. We find that the range of $g-r$ and $r-z$ surface colors of the 10 plutinos is inconsistent with that of the 13 cold classical objects, where the majority of the cold classical objects lie redward of the plutinos in $g-r$ and $r-z$. The differences in their surface color distributions is statistically significant, with minimal overlap of the two distributions at comparatively neutral colors. Our comparison of the surface color distributions of the plutinos, cold classicals, and 19 nonresonant dynamically hot TNOs implies that the population of nonresonant dynamically hot TNOs contains a mixture of the surface types present in the plutinos and cold-classicals. The intrinsic fraction of plutinos with cold classical type colors is a valuable observational constraint to models of Neptune's migration and radial extent of the primordial cold classical belt. We compare our results with the $g-r$ and $r-J$ surface color distribution of plutinos from the Col-OSSOS survey and discuss the consistency of these color measurements with proposed dynamical histories of the current plutino population.