IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2021A065 PROGRAM_TITLE Gas-phase refractory material around Chi Cyg: Investigating the role of dust formation chemistry in an S-type Mira star. PROGRAM_INV1 Guido Fuchs PROGRAM_INV2 Daniel Witsch PROGRAM_INV3 Thomas Giesen PROGRAM_INV4 Thomas Greathouse PROGRAM_INV5 John Lacy PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG The star Chi Cyg is one of the best examples of an S-type Mira variable and is only 169 pc away from us. It is an asymptotic giant branch star [AGB] with a low surface temperature, which appears in the sky as a bright infrared object. The goal for this observational program is a first-time detection of the molecules Al2O and TiO at mid-IR frequencies towards this star by means of their ro-vibrational spectra. With the detection of these molecules a better understanding of dust formation processes can be achieved. In addition, other important molecules like SiO, NH3, and CO2 will be observed and used to characterize the phase conditions of the variable star. Furthermore, SiO observations will also be used to investigate the isotopic abundances of silicon. Both Al2O and TiO have recently been studied in our laboratories and accurate line lists have been prepared. For these observations a high frequency resolution is necessary to unambiguously identify these molecular species in the gas-phase. The TEXES spectrograph on IRTF with a resolution better than 65,000 is ideally suited for the proposed project. PROGRAM_ABSTRACT_END