# # Program information file # PROGRAM_ID 2022B078 PROGRAM_TITLE Spectro-astrometry of the planet-forming regions of circumstellar disks PROGRAM_INV1 Jonathan Williams PROGRAM_INV2 Adwin Boogert PROGRAM_INV3 Matt Richter PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG We propose to observe the circumstellar disks around three young protostars in Taurus with iSHELL at M-band to a high signal-to-noise ratio in order to measure the spectro-astrometric signal [change of position with velocity] of the numerous CO and H2O lines in the bandpass. This will allow us to infer the physical and chemical structure of the inner, planet-forming regions of the disk at sub-au resolution. This data will complement scheduled observations in a JWST-MIRI GTO program and existing high resolution ALMA data of the outer disk, ultimately providing one of most complete and detailed views of each disk. This work will become a baseline for future monitoring studies from which we can learn about disk winds, shocks, stochastic events, and instabilities. PROGRAM_ABSTRACT_END