Discovery of Two Nearby Post-T Tauri Stellar Associations

Abstract

In this work we report the discovery of two new stellar associations in close vicinity of the Sun at roughly 180 and 150 pc. These two associations, u Tau assoc and e Tau assoc, were detected based on their clustering in a multi-dimensional parameter space including α, δ, μ_α, μ_δ, and ϖ of Gaia. The fitting of pre-main-sequence model isochrones in their color-magnitude diagrams suggests that the two associations are of about 50 Myr old and the group members lower than ∼0.8 M_⊙ are at the stage of post-T Tauri.