2025ApJ...984...58H

We present a new processing of XP spectra for 220 million stars released in Gaia DR3. The new data model is capable of handling objects with T_eff between 2000 and 50,000 K and with $\mathrm{log}\,g$ between 0 and 10, including objects of multitude of masses and evolutionary stages. This includes for the first time ever robust processing of spectroscopic parameters for pre-main-sequence stars, with $\mathrm{log}\,g$ sensitivity toward their age. Through this analysis we examine the distribution of young low-mass stars with ages of up to 20 Myr in the solar neighborhood, and we identify a new massive (>1000 stars) population, Ophion, which is found east of Sco-Cen. This population appears to be fully disrupted, with negligible kinematic coherence. Nonetheless, due its young age it appears to still persist as a spatial overdensity. Through improved determination of ages of the nearby stars, it may be possible to better recover the star-forming history of the solar neighborhood outside of the moving groups.