# # Program information file # PROGRAM_ID 2023B036 PROGRAM_TITLE High precision near-infrared light curve of the dwarf planet Eris PROGRAM_INV1 Robert Szakats PROGRAM_INV2 Csaba Kiss PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT Centaurs / TNOs / KBOs PROGRAM_ABSTRACT_BEG Recent measurements indicate a significant J-H near-infared rotational color variations of the dwarf planet Eris. Several molecules [e.g. CH4, CH3OH] have strong absorption bands close to the H photometric band and these molecules might be responsible for the surface compositional variegations that are seen as different J-H colors at different sub-observer longitudes. Here we propose to obtain high precision J and H-band light curves of Eris with the Guidedog Camera of the Infrared Telescope Facility to i] confirm the existence of the NIR color variations of Eris, ii] determine the actual phasing with the visible range light curve, iii] identify the main surface materials that could be responsible for the near-IR color variation. This is an important step in the understanding of the surface composition of dwarf planets as currently we have limited information about these compositional variegation on bodies other than the Pluto-Charon system in the trans-Neptunian region. PROGRAM_ABSTRACT_END