Location of the investigated objects (large dots) in the CMD of ω Cen. Circles: photometric variables. Crosses: radial-velocity variables. Triangles: suspected radial-velocity variables. Ellipses 1, 2, and 3 indicate the approximate locations of the occupied regions, respectively, by blue, yellow, and red stragglers (see also Sect. 1). The background CM-diagram is from our unpublished photometry of a 2.6  ×  2.6 arcmin field centered at α = 13^h27^m42 2, δ = –47°23′34′′, obtained on the 2.5-m duPont telescope at Las Campanas Observatory.