  We show that topologically protected defect states can exist in open (leaky
or lossy) systems even when these systems are topologically trivial in the
closed limit. The states appear from within the continuum, thus in absence of a
band gap, and are generated via exceptional points (a spectral transition that
occurs in open wave and quantum systems with a generalized time-reversal
symmetry), or via a degeneracy induced by charge-conjugation-symmetry (which is
related to the pole transition of Majorana zero modes). We demonstrate these
findings for a leaking passive coupled-resonator optical waveguide with
asymmmetric internal scattering, where the required symmetries (non-hermitian
versions of time-reversal symmetry, chirality and charge-conjugation) emerge
dynamically.
