Presentation #319.04 in the session “A Smorgasboard of Comets”.
We present here observations of the comet C/2017 U7 obtained in 2018 and 2019 using the red camera of Goodman High Throughput Spectrograph (GHTS) at SOAR telescope. This comet was discovered in 2017 and found to have an hyperbolic orbit. We obtained visible spectra covering the wavelength range of 0.5–0.9 µm and also images in the SDSS filter system. Both the low-resolution reflectance spectrum and the reflectance spectra derived from the SDSS filters show an atypical band at ~ 0.6 µm. We conducted a comparative study of the colors and reflectance spectra of different small body populations (comets, Centaurs, and Trans-Neptunian objects) from the literature and concluded that the spectra and the colors of this comet are atypical, showing some overlap only with some members of the TNOs, within the large uncertainties of the measurements of that population. Thus, our measurements show an atypical band, which might be indicative of an peculiar composition.