Evidence that the active stars HD 102077 (V 838 Cen) and HD 139084 (V 343 Nor) are members of the Local Association

Abstract

The space motions, rotational |$\upsilon \enspace\text {sin}\enspace i$| values and lithium abundances are determined for the two southern-hemisphere active-chromosphere stars HD 102077 and 139084. The results imply that both stars are likely members of the Pleiades group as defined by Eggen (⁠|$V = -25\enspace\text {km}\text s^{-1}$|⁠). This indicates an age of |$7-10 \times 10^7$| yr, consistent with the derived lithium abundance. Photometric data are also presented and compared with previous observations, to provide evidence for changes in the spot-induced light curves for each star.