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The precise parallax, proper motion, and photometric measurements containedin Gaia Data Release 2 (DR2) offer the opportunity to re-examine the membershipand ages of Nearby Young Moving Groups (NYMGs), i.e., loose groups of stars ofage $\lesssim100$ Myr in the solar vicinity. Here, we analyze the available DR2data for members and candidate members of the $\epsilon$ Cha Association($\epsilon$CA) which, at an estimated age of $\sim$3--5 Myr, has previouslybeen identified as among the youngest NYMGs. The several dozen confirmedmembers of $\epsilon$CA include MP Mus and T Cha, two of the nearest stars ofroughly solar mass that are known to host primordial protoplanetary disks, andthe Herbig Ae/Be star HD 104237A. We have used Gaia DR2 data to ascertain theGalactic positions and kinematics and color-magnitude diagram positions of$\epsilon$CA members and candidates, so as to reassess their membership statusand thereby refine estimates of the distance, age, multiplicity, and diskfraction of the group. Our analysis yields 36 \textit{bona fide} $\epsilon$CAmembers, as well as 20 provisional members, including 3 new members identifiedhere as comoving companions to previously known $\epsilon$CA stars. Wedetermine a mean distance to $\epsilon$CA of 101.0$\pm$4.6 pc and confirm that,at an age of $5^{+3}_{-2}$ Myr, $\epsilon$CA represents the youngest stellargroup within $\sim$100 pc of Earth. We identify several new photometric binarycandidates, bringing the overall multiplicity fraction (MF) of $\epsilon$CA to40\%, intermediate between the MFs of young T associations and the field.

Gaia-based Isochronal, Kinematic, and Spatial Analysis of the $\epsilon$ Cha Association