# # Program information file # PROGRAM_ID 2024A989 PROGRAM_TITLE Do FUors really have a Keplerian disk? PROGRAM_INV1 Mike Connelley PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG We plan to measure the line profiles of CO fundamental at 4.6 micron for 10 FU Orionis eruptive variables. If the CO lines are photospheric in origin, then we expect to see single-peaked symmetrical CO profiles similar to what we see at 2.3 um, and similar to the line profiles of a late type star. However, if the CO lines are from a disk, then we expect to see line profiles similar to those seen in T Tauri stars. We plan to use iSHELL in M-band with the 0.75 arcsec slit to observe the CO fundamental line transition near 4.6 microns. We have chosen stars that are brighter than M=6, so that we can get to S/N=100 in an hour or less. PROGRAM_ABSTRACT_END