# # Program information file # PROGRAM_ID 2022A006 PROGRAM_TITLE Spectroscopy of 20 Myr-old Stars with Circumstellar Disks PROGRAM_INV1 Kevin Luhman PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT galactic/interstellar medium PROGRAM_ABSTRACT_BEG We have used high-precision astrometry and photometry from Gaia and mid-IR photometry from WISE to identify ~500 likely members of the Sco-Cen complex that have ages of 20 Myr and that exhibit evidence of circumstellar disks. These sources comprise the largest available sample of primordial disks at an age beyond 10 Myr, and thus are highly valuable targets for studies of the evolution of primordial disks and the formation of giant planets, particularly with ALMA. However, most of these stars have not been observed previously with spectroscopy, so they lack basic measurements necessary for followup disk studies, such as spectral classifications and confirmation of youth. We propose to use SpeX to perform those spectroscopic measurements for the targets that are observable from the IRTF. PROGRAM_ABSTRACT_END