# # Program information file # PROGRAM_ID 2024A007 PROGRAM_TITLE Synoptic SpeX & MATISSE Observations of Planet-Hosting PMS Disks PROGRAM_INV1 Michael Sitko PROGRAM_INV2 Ray Russell PROGRAM_INV3 Jozsef Varga PROGRAM_INV4 Bruno Lopez PROGRAM_INV5 William Danchi PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Recent observations of the Herbig Ae star HD 163296 with the Very Large Telescope Interferometer indicate structural changes are occurring near the inner edge of its disk, about 0.3 AU from the star. These might signal perturbations due to turbulence or a pressure bump from an embedded or slightly external exo-protoplanet. Both Guaranteed Telescope Observations and Guest Observations of HD 163296, and about a dozen more Herbig Ae and T Tauri stars, are planned for these stars using the MATISSE 4-telescope beam-combining instrument on the VLTI at L, M, and N bands over the next year. Spectroscopic and photometric observations overlapping the MATISSE observations with SpeX on the IRTF are needed to aid in the interpretation of the interferometry. MATISSE observations using 4 Auxiliary Telescopes [ATs], each with a 1.8 m diameter, will be used with the newest, largest baselines [finer details], making it equivalent to a single dish with a diameter of 200 meters. These objects are variable stars, so that to sample SpeX spectra and MATISSE interferometry at the same physical state, they need to be observed as close in time as possible, so that their combined information represents the same stare. Spectroscopy on one date and interferometry at another date might represent vary different physical states. Time scales range from 0.7 days to ~ 8 months. This is a long-term program and more time will be requested in 2024B. PROGRAM_ABSTRACT_END