IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2023B089 PROGRAM_TITLE Studying time-variable accretion of the Orion protostars using SPEX Spectroscopy PROGRAM_INV1 Rohan Rahatgaonkar PROGRAM_INV2 Tom Megeath PROGRAM_INV3 Will Fischer PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG We propose the 2nd and 3rd epoch in a multi-epoch study of accretion variability toward three flat spectrum protostars in Orion that were studied by the HOPS program. These were selected on the basis of SpeX SXD/LXD observations from 2010/2006 that show bright line emission. While protostars during their primary accretion phase are too deeply embedded to study in the near-IR, these objects may provide analogs to the early, rapid accretion phase. All three show bright Paschen and Brackett series emission lines tracing the rapid flow of material through accretion columns. Comparing the spectra to the previous epoch, we will look for changes in the accretion rate, reddening, and in the properties of the gas in the flows. This will be followed by further observations in the next semester to look at variations on shorter scales. Together, these will provide an examination of variations on decade, year, month scales - providing constraints on the processes in protostellar disks producing the variability. PROGRAM_ABSTRACT_END