Water absorption band in V1309 Sco (black) is compared to simulations of the ρστ band at different excitation temperatures (see Appendix A). The observed band cannot be formed as a telluric feature because the structure of the band at air temperatures does not form a clear band-head near 926 nm. All simulations were smoothed to fit the width of the observed features. Although water dominates, there are additional opacity sources in this wavelenght range, e.g. the TiO ϵ system.