# # Program information file # PROGRAM_ID 2023B010 PROGRAM_TITLE Spectroscopy of Unusually Old Stars with Primordial Disks PROGRAM_INV1 Kevin Luhman PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Planets are born within the primordial circumstellar disks that surround newborn stars. Primordial disks become increasingly rare at older ages because of giant planet formation and other processes that disperse them. Although they are rare, the oldest of these disks [>10 Myr] are valuable for studies of the final stages of giant planet formation and the dispersal of disks. A recent study has used Gaia DR3 data to identify >1000 members of several nearby associations with ages of 13-56 Myr. Fourteen of those members exhibit IR excesses from disks in data from WISE but lack previous spectroscopy. We propose to use SpeX to measure their spectral types and confirm their youth, which will facilitate detailed studies of their disks by facilities like ALMA. PROGRAM_ABSTRACT_END