A Pre-Gaia Census of Nearby Stellar Groups

Abstract

The nearest, youngest groups of stars to the Sun provide important samples of age-dated stars for studying circumstellar disk evolution, imaged exoplanets, and brown dwarfs. I briefly comment on the status of the known stellar groups within 100 pc: $\beta$ Pic, AB Dor, UMa, Car-Near, Tuc-Hor and $\beta$ Tuc nucleus, Hyades, Col, TW Hya, Car, Coma Ber, 32 Ori, $\eta$ Cha, and $\chi^1$ For. I also discuss some poorly characterized groups and "non-groups." Grades for 2015 of Pass, Satisfactory, or Fail are assigned to the groups for the purposes of age-dating stars and brown dwarfs. I speculate that Tuc-Hor could have provided a supernova ~60 pc away ~2.2 Myr ago which showered the Earth with traces of 60Fe-bearing dust.Comment: 6 pages, Proceedings IAU Symposium No. 314, Young Stars & Planets Near the Sun, 2015, J. H. Kastner, B. Stelzer, & S. A. Metchev, ed