2018ApJ...863...91F

We present a reorganization of the Oh et al. wide, comoving catalog of 4555 groups of stars (10,606 individual objects) identified in the Tycho Gaia Astrometric Survey (TGAS) into new and known coevolving groups of stars in the Milky Way. We use the BANYAN Σ kinematic analysis tool to identify 1015 individual stars in the Oh et al. catalog that yielded a >80% probability in 1 of 27 known associations (e.g., the AB Doradus moving group, Columba, Upper Scorpius) in the vicinity of the Sun. Among the 27 groups uncovered by Oh et al. that had >10 connected components, we find that 4 are newly discovered. We use a combination of Tycho, Gaia, Two micron All Sky catalog, Wide Field Infrared Survey Explorer Mission, Galaxy Evolution Explorer, and Rontgen Satellite photometry as well as Gaia parallaxes to determine that these new groups are likely older than the Pleiades but younger than ∼1 Gyr. Using isochrone fitting, we find that the majority of these new groups have solar-type stars and solar-type metallicity. Among the 35 Oh et al. groups with five to nine members, we find that 19 also appear new and comoving, with Oh et al. Group 30 is particularly exciting as it is well within 100 pc (range of 77-90 pc) and also appears to be older than the Pleiades. For known star-forming regions, open clusters, and moving groups identified by Oh et al., we find that the majority were broken up into pieces over several Oh et al. groups (e.g., Lower Centaurus Crux members are spread over 26 Oh et al. groups); however, we found no correlation with positions of the groups on color-magnitude diagrams, and therefore no substructure of the association correlated with the Oh et al. designated group. We find that across the 27 groups tested by BANYAN Σ there were 400 new members to 20 different associations uncovered by Oh et al. that require further vetting.