# # Program information file # PROGRAM_ID 2024B989 PROGRAM_TITLE Phaeton Spectroscopy for Destiny Mission PROGRAM_INV1 Simone Ieva PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT near-Earth objects PROGRAM_ABSTRACT_BEG This is a DDT proposal to characterize (3200) Phaethon in scientific support of the DESTINY+ mission. Phaethon is an extremely interesting near-Earth object, originally discovered as an asteroid, but with frequent activity close to perihelion that has potentially been associated with sodium emissions. We are currently approaching perihelion and with the imminent launch of DESTINY+, this will be the last opportunity to characterize the target and greatly enhance the scientific return of the mission. Taking advantage of a close passage in December 2024, we propose to obtain new spectral data of the system in the near-infrared using SpeX. We plan to obtain spectra at different rotational phases, in order to cover a full Phaethon rotational period (3.6 h). With the current geometry we could confirm if the variations we see in spectra in literature are due to different grain sizes between northern and southern hemisphere, or are due to compositional heterogeneity. We propose to use the Prism mode of SPEX spectrograph. Assuming an average sun-like V-K color for Phaethon (~1.6), an average Vmag during the period considered (V=16.5), and using very conservative constraints on the ETC (seeing at 2.2 um of 1.2 arcsec, slit of 1.6 arcsec, total integration time of 15 min), we obtain a S/N > 50 for all the wavelength regions up to 2.4 um. This S/N is perfectly adequate to identify mineralogical bands and constrain spectral slope. PROGRAM_ABSTRACT_END