Program: GN-2022A-FT-204

We wish to search for young brown dwarfs at planetary masses (<10 Jupiter masses) in nearby star- forming regions to 1) test star formation theories by constraining the minimum mass of the Initial Mass Function, 2) enable the identification of signatures that can distinguish between planets and brown dwarfs (with JWST), and 3) enable the measurement of the lowest mass at which brown dwarfs harbor the materials for making planets (with JWST). The Upper Sco association is one of the most promising hunting grounds for young planetary-mass brown dwarfs due to its proximity and richness (145 pc, ~2000 members). Using photometry and proper motions from several optical and IR surveys, we have identified a few dozen candidate members of Upper Sco that could have masses as low as 5-6 Jupiter masses. We propose to use GNIRS to obtain spectra of a subset these candidates to verify their cool nature and their youth (and hence their membership in Upper Sco).