3D galactic view of the η Cha cluster and its surrounding halo of young stars. The Sun is located at (0,0,0), the x-axis is directed toward the Galactic center, the y-axis in the direction of galactic rotation, and the z-axis lies perpendicular to the Galactic plane. Large circles indicate known (red) and new (yellow) members, small circles denote stars found in our core (blue) and extended search region (red), as defined in Sect. 3.1.