# # Program information file # PROGRAM_ID 2024A017 PROGRAM_TITLE Assessing an apparent mid-infrared fade/burst cycle for R Coronae Borealis stars PROGRAM_INV1 Carl Melis PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Investigating the most mid-infrared variable R Coronae Borealis [R CrB] stars found in IRAS, AKARI, and WISE data reveals long-term fading trends, bursts that can show a factor of up to 10 change in flux density between epochs, and blackbody-fit temperatures that span 400-1300 K. There is no obviously discernible correlation between mid-infrared flux level and optical dust obscuration events, although the available data set suffers dramatic gaps in temporal coverage. We seek to monitor with MIRSI a small set of R CrB stars throughout an entire fade/burst cycle to probe whether there is any preferred timescale for their mid-infrared variability and circumstellar dust temperature changes, and if these are correlated with optical dimmings. These data will provide an unprecedented view into the evolution of R CrB star circumstellar material and help elucidate its origin. PROGRAM_ABSTRACT_END