# # Program information file # PROGRAM_ID 2024A009 PROGRAM_TITLE Investigation of the Spectral Variability of MWC 922 [the Red Square] PROGRAM_INV1 Michael Sitko PROGRAM_INV2 Ray Russell PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG MWC 922 is the central star of the Red Square nebula. It displays structures due to major ejection events on time scales [likely] of centuries. It contains a binary star. Currently the orbital period is not known [yet], but for a similar object, HD 44179 [Red Rectangle] it is ~317 days. MWC 922 exhibits emission bands of organic species near 3 microns, and many atomic lines in emission throughout its 0.8-5 micron spectrum as well as 2 bands of CO. Yet, the precise way organic bands are formed is not known. Spectrographs with wavelength coverage between 2.5 and 5 microns are rare, so the LXD mode of SpeX is particularly valuable. MWC 922 is virtually unexplored in this spectral region, but the similarity of the morphology of the Red Square to the Red Rectangle suggests a similar physical nature. MWC 922 was successfully observed with SpeX SXD+LXD on April 23, 2023. The project proposed here with be the next step to obtain synoptic 1-5 micron spectra of this fascinating object. Three nights are requested, and each will have a different position angle of the slit on the sky. PROGRAM_ABSTRACT_END