IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2024A060 PROGRAM_TITLE Search for 3-micron Features on Near-Earth Objects PROGRAM_INV1 Lauren McGraw PROGRAM_INV2 Cristina Thomas PROGRAM_INV3 Josh Emery PROGRAM_INV4 Andy Rivkin PROGRAM_INV5 PROGRAM_SCICAT near-Earth objects PROGRAM_ABSTRACT_BEG Our goal is to collect near-infrared LXD data with the SpeX instrument at the IRTF for four near-Earth objects [NEOs] in order to identify whether these airless bodies exhibit a 3-um OH/H2O absorption feature. Solar wind hydrogen implantation, carbonaceous or cometary material impacts, and native phyllosilicates are three sources or mechanisms by which OH/H2O is delivered to airless bodies. These mechanisms are known to be active in near-Earth space, but it remains unclear how effective they are on asteroids and what factors control and/or influence them. We propose an NEA spectral survey that will use the SpeX instrument to obtain prism and LXD short observations of all NEAs of sufficient brightness [V < 14] and airmass [AM<2] for 6 hours. Our LXD observations would represent a sizeable increase in the population of NEAs with such spectral data as fewer than 40 3-um spectra of NEAs currently exist, including those from spacecraft missions. The 3-um feature generally has a band depth of a few percent on nominally anhydrous bodies to tens of percent on bodies with native phyllosilicates. We therefore require S/N ~ 50 over the wavelength range 2 -- 4 um to ensure detection of the shallowest expected bands. SpeX in LXD mode can achieve this requirement for asteroids with V<14 [after binning] with total telescope time of ~6 hrs. Four NEAs achieve this brightness in 2024A and we propose to observe them all. PROGRAM_ABSTRACT_END