Astromat

UV bidirectional relative reflectance spectra of OSIRIS-REx returned sample OREX-800029-0 (200 mg of Bennu aggregate, bulk material from the TAGSAM head, delivered in an Eagle stainless steel container) were acquired using an Ocean Optics Maya2000 Pro spectrometer (250-500 nm). Measurements were conducted under ambient air conditions (temperature 23.7 degrees C, relative humidity 6.8%) on January 18, 2024. The sample was poured unsorted into an aluminum cup (12.5 mm wide, 3.25 mm deep, bevelled). Five spectra were acquired at 5 spots at normal incidence and emission (i=0, e=0, phase=180) using a 30 W AIS mini-DTA UV light source with collimating lens and an Ocean Optics solarization-resistant bifurcated fiber optic (6 illumination fibers, 1 pickup). Integration time was 200 ms with 200 scans averaged. Spot 2 was centred on a bright grain (spot K); remaining spots were random. Spectra were calibrated against a Fluorilon reference standard and corrected for Fluorilon absorption features. All spectra are reported as relative reflectance. The sample was neither heated nor vacuum-exposed prior to measurement.