# # Program information file # PROGRAM_ID 2024B074 PROGRAM_TITLE Catching Centaur Activity in the Act: ToO Outburst Studies PROGRAM_INV1 Theodore Kareta PROGRAM_INV2 Megan Firgard PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT Centaurs / TNOs / KBOs PROGRAM_ABSTRACT_BEG While the comets of the inner Solar System are powered by the sublimation of solid water ice, understanding the mechanisms that power cometary activity at larger distances has proven challenging -- especially from the ground, as the most-likely-culprit volatiles [carbon monoxide and dioxide] are challenging to observe through the Earth's atmosphere. In this proposal, we are asking for ToO time to study an outburst [a sudden onset or increase of cometary activity] on a Centaur -- a class of solar system objects on chaotic, giant-planet-crossing orbits which occasionally show cometary activity. We aim to not just capture the reflectance spectrum of an object when it first throws off gas and dust at the start of the outburst, but also in the days after to see how the way the expanding material reflects light changes. Our experimental design is motivated by previous successful ToO programs in the near-infrared at the IRTF and elsewhere. If the reflectance spectrum of the Centaur's coma does change as a function of time as expected, we should be able to construct and constrain models of not just what kinds of materials were ejected, but also the quantity and velocity of gas[ses] required to accelerate that dust. In other words, even if we cannot see the gasses we are interested in from the ground, we may be able to constrain their properties and motion -- a significant step forward which may help interpret future and extant space telescope data. PROGRAM_ABSTRACT_END