# # Program information file # PROGRAM_ID 2021A011 PROGRAM_TITLE V3890Sgr at Quiescence PROGRAM_INV1 Chick Woodward PROGRAM_INV2 Anuerin Evans PROGRAM_INV3 Yakiv Pavlenko PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG V3890Sgr, an unusual and exotic recurrent nova [periododicity of roughly 20yrs and gamma-ray transient recently in outburst, is returning to quiescence. The science goal of this SpeX SXD+LXD proposal is to obtain high-signal-to-noise [several 100 in the continuum] absorption features associated with various isotopologues of CO and SiO band heads. Whether or not these features arise from the photosphere of the M-giant secondary or the circumbinary medium of the system may be ascertained from the isotopic ratios of C, O, and Si. Spectra at quiescence will enable comparative analysis with the spectra obtained early after outburst to identify changes in the physical conditions of the V3890Sgr system and abundances and isotopic ratios of the companion. PROGRAM_ABSTRACT_END