pointing to the Vernal Equinox, the $\eta$-axis to $\alpha = 90\deg$ and the $\zeta$-axis points to the Equatorial North Pole.]{}]{} The vector $\vec{R_c}$ is measured in parsec and is the position vector of the center of the group, and $\vec{V_c}$, in $\rm km~s^{-1}$, is the vector of the space velocity of the group; [$\vec{V_{c}}/{{\|\vec{V_{c}}\|}}$]{} being the Cartesian equatorial coordinates of the convergent point.

[[*Gaia*]{}]{} DR2 now enables to study the groups A and B in great detail. In a first step we made a query of the [[*Gaia*]{}]{}DR2 catalog consisting of a cone search around $(\alpha,\delta)$ = (186.5, -60.5) with a radius of 20 degrees. [[The center of the cone has been chosen midway between our groups A and B from TGAS and the radius large enough to contain both groups.]{}]{} Further we applied the following restrictions: for the trigonometric parallax ; for the proper motions -43 mas/y $\leq \mu_{\alpha*} \leq$ -20 mas/y ($\mu_{\alpha*} \equiv \mu_\alpha \cos\delta$), and -35 $\leq \mu_{\delta} \leq$ +12 mas/y. The proper motion and parallax cuts were chosen to be consistent with the distribution of stars identified as members of these probable young moving groups we revealed in TGAS. [[This query yielded 20,138 objects and we 