2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4838We obtained near-infrared spectra of a sample of very low mass objects as a function of age in order to investigate the temperature and surface gravity sensitivity of several features in the J and K bands.2 pages, in newpasp.sty format, 1 figure. To be published in the Proceedings of IAU Symposium 211Astrophysicstext