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# Program information file
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PROGRAM_ID           2023A002
PROGRAM_TITLE        Synoptic Observations of the Central star and Inner Nebular Regions of HD 44179 [Red Rectangle] and MWC 922 [Red Square].
PROGRAM_INV1         Michael Sitko
PROGRAM_INV2         Ray Russell
PROGRAM_INV3          
PROGRAM_INV4          
PROGRAM_INV5          
PROGRAM_SCICAT       stellar
PROGRAM_ABSTRACT_BEG
HD 44179 and MWC 922 are the central stars of the Red Rectangle and Red Square nebula, respectively. These display structures due to major ejection events on time scales of centuries. But both contain close binary stars. The orbital period of HD 44179 is ~200 days, while that of PWC 922. Both exhibit emission bands of organic species at 3-12 microns. Yet, the precise way these are formed is not known. Of the two, HD 44179 is better-studied, but synoptic IR spectroscopic observations on orbital time scales have yet to be obtained. The peak continuum brightness [in lF[l] W/m^2] is at 2.5 um, implying T[dust] ~1500 K. This is especially true for instruments capable of obtaining spectra st 3.3 um, as few instruments exist that can't spectra at that wavelength. SpeX LXD thus can make fundamental contributions to our understanding of the circumstellar regions where organics are produced. 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. The project proposed here with be the first step to obtain synoptic 1-5 micron spectra of these fascinating objects.
PROGRAM_ABSTRACT_END