Fig. 4

A trajectory \(c^{s}_{\varepsilon }\) (green) on the saddle slow manifold \(S^{s}_{\varepsilon }\) and its stable manifold \(W^{s}(c^{s}_{\varepsilon })\) (blue) and unstable manifold \(W^{s}(c^{s}_{\varepsilon })\) (red) in system (11) with \(\mu =9.2\) and \(\varepsilon =0.01\). A selection of orbit segments of \(W^{s}(c^{s}_{\varepsilon })\) and \(W^{s}(c^{s}_{\varepsilon })\) are shown as blue and red thick curves, respectively. Panel (a) shows the stable manifold \(W^{s}(c^{s}_{\varepsilon })\), panel (b) shows the unstable manifold \(W^{u}(c^{s}_{\varepsilon })\) and panel (c) shows both