📝 SummarXiv

Abstract

We re-evaluate the star formation history of the nearby Sco-Cen OB Association with a comprehensive analysis of Gaia XP spectra of more than 7,800 potential members. New spectral classifications are obtained by fitting individual XP spectra with templates derived from empirical spectra of young stars. Combining these spectral classifications in this work and in the literature with archival photometry leads to estimates of V-band extinction and stellar luminosities for a total of 8,846 sources. Employing SPOTS models with spot coverages of 0.34 and 0.51 for K and M-type stars harmonizes age estimates between K/M-type and F/G-type stars, with ages older than are obtained for low-mass stars from standard evolutionary models. These older ages lead to a disk lifetime that is approximately two times longer than reported in previous literature. Our re-evaluation of the star formation history with these revised age estimates uncovers evidence of underlying substructures within the Sco-Cen complex.