# # Program information file # PROGRAM_ID 2021B121 PROGRAM_TITLE Infrared spectroscopy to support an optical interferometric study of symbiotic stars PROGRAM_INV1 Ryan Norris PROGRAM_INV2 Michelle Creech-Eakman PROGRAM_INV3 Thomas Gaudin PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Symbiotic stars are interacting binary systems comprised of a cool star and hot object, often a white dwarf. Although they have some of the longest periods of any interacting binaries, they do experience mass transfer and may be one of the channels toward Type Ia supernovae. In order to better understand mass-loss in these systems we are pursing optical interferometric imaging of four systems with the CHARA Array: V1472 Aql, BD Cam, SU Lyn and EG And. Those measurements will enable us to measure the radius of the star, determine the Roche filling factor, and detect signs of mass-loss. To interpret those data, we require near contemporaneous spectroscopy of these stars with SpeX. This will enable us to determine the stellar parameters of the cool star and detect evidence of circumstellar material which would influence the interpretation of the images. All this will help us constrain mass-loss models used to interpret other systems. We are requesting to use SpeX to obtain SXD and LXD spectra at R~2500 using the 0.3x15' slit. Although it requires more time, we request LXD because these stars have infrared excess at longer wavelengths which may influence our interpretation of the interferometric images. We have requested two nights, each pseudo-contemporaneous to the CHARA observations. The CHARA runs are in August and early November and thus we request time around then. In each run, we will observe three-four stars. Although these stars are bright, taking in to consideration the time needed to obtain sufficient SNR [SNR>25] on calibrators and the longer overhead for LXD observations, we estimate that we we will need 2.3 hours to observe each target and thus seven hours on the night in which we can observe three stars and nine on the night in which we can observe four. PROGRAM_ABSTRACT_END