Hunting for Long-lived Protoplanetary Disks Observed with AKARI/FIS

Abstract

Twenty-one YSOs (Young Stellar Objects) in the solar neighbor have been identified through cross-correlating Hipparcos catalog with AKARI/FIS YSO catalog. The reliability of the match is over 90%. The central objects cover spectral types from B to M. The Hipparcos parallaxes enable us to place the objects in the H-R diagram, which can be used to determine their ages by isochrones. Among these objects, two YSOs have been found whose ages are larger than 10 Myr. The optical to infrared spectral energy distributions (SEDs) of these two YSOs are consistent with those of type II YSOs with protoplanetary disks. Furthermore, from the SED fitting, the ages of these two sources are constrained to (14.1±4.2) Myr and (16.8±4.4) Myr, respectively. Therefore, two YSO candidates with long-lived protoplanetary disks have been detected in AKARI/FIS. The presence of long-lived protoplanetary disks has significant implications for the formation of planets and their host stars.