Program: GN-2020B-Q-405

Comets and their parent source regions (Trans-Neptunian objects, Centaurs, Oort cloud objects) contain mostly pristine materials from the earliest stages of our Solar System’s formation. A better understanding of these objects provides insights into the early planetesimals that went into making the giant planets. Results from spacecraft visited comet nuclei have confirmed the long-standing view that the majority of cometary-like activity has sub-surface nuclear origins. Thus, the observational characterization of gas and dust comae indirectly probes into the compositional nature of the inaccessible and more thermally pristine nucleus sub-surface layers. The James Webb Space Telescope (JWST) will allow for the first-time thorough observational constraints of gas comae for small bodies active in a region too distant to be driven by the sublimation of water ice. These future observations will provide critical diagnostics for constraining models of outgassing behavior and comet-forming environments. In order to prepare for future JWST observations, we propose acquiring new Gemini-GMOS r’ imaging of a strategically selected group of Centaurs with known periods of activity and distantly active comets in order to (1) monitor their activity behaviors allowing predictions for their state of activity during to-be proposed follow-up JWST comae characterization, enabling target selection and (2) determine high-precision astrometry for individual objects, enabling improved ephemerides with decreased positional uncertainty for efficient JWST spectroscopy. Monitoring and characterization of these objects now will allow more efficient utilization of the future JWST observational resources to better understand distant cometary-like activity.