Abstract
We present a number of late type main-sequence stars whose strong chromospheric activity would imply ages significantly smaller than those given by their kinematics. We discuss processes which may explain this inconsistency, and conclude that the most likely explanation is the rejuvenation of the primary component of a close binary (P less than 5 days), either by the spin-up induced by the loss of orbital angular momentum through their magnetized winds, or by the final coalescence of the close pair. By analogy with the blue straggler phenomenon we propose to call the coalesced objects 'red stragglers', since they straggle out of their expected position in velocity space.
