# # Program information file # PROGRAM_ID 2023A078 PROGRAM_TITLE Time-Series Infrared Spectroscopy of an Inner Protoplanetary Disk PROGRAM_INV1 Eric Gaidos PROGRAM_INV2 Andrea Banzatti PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Observations of protoplanetary disks around T Tauri stars inform us as to the processes and environment of planet formation. While the outer [>>1 au] disks of many T Tauri stars can now be directly resolved by telescopes such as ALMA, the inner regions of the disks which spawn most of the exoplanets known, i.e. detected by Kepler. Observations of variability on hours to months, corresponding to orbital semi-major axes of <<1 au, are a means to probe such regions, e.g., as dust from a circumstellar disk occults the central star and the material's structure, dynamics, and composition can be studied. We propose multi-epoch infrared [iSHELL] spectroscopy of the 1-3 Myr-old member of the Lupus molecular cloud GQ Lup, to study variability in the lines of H, He and CO in concert with visible light monitoring by the TESS satellite during Sector 65 [May 2023]. Our objectives are: [1] measure variability in profile of the 1.083-micron triplet He I line that indicates simultaneous absorption by a wind and accretion flow; [2] search for emission in the 1.282-micron Paschen_eta line of H I, an indicator of outflows in T Tauri stars; [3] correlate variability in the molecular CO line with photometric variability and [4] exploit the rapid rotation of this young star and the Rossiter-McLaughlin effect to constrain the structure and orbital motion of the occulting dust. PROGRAM_ABSTRACT_END