# # Program information file # PROGRAM_ID 2024A071 PROGRAM_TITLE Striking while the Iron is Hot: Supernova Physics in the Infrared PROGRAM_INV1 Willem Hoogendam PROGRAM_INV2 Ben Shappee PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT extra-galactic PROGRAM_ABSTRACT_BEG We request 12 hours of ToO observations to acquire early-time NIR spectra of Type Ia supernovae [SNe Ia] using the SpeX instrument. We will use these crucial early-time data to measure the amount of unburnt carbon, estimate the completion time of nuclear burning, derive upper limits on any potential hydrogen or helium, and explore differences in the early NIR spectra of peculiar SNe Ia. With these measurements, we will differentiate between various progenitor scenarios for our SNe Ia sample, specifically between the sub-Chandrasekhar mass versus Chandrasekhar mass and companion versus no companion scenarios. Objects will be observed via ToO requests to enable the earliest possible initial data. Currently, there is a dearth of early NIR observations for peculiar SNe Ia. These early NIR spectra will provide new data, some of which will be the first-ever early-time NIR spectra for some SNe Ia subtypes. PROGRAM_ABSTRACT_END