  We estimate the maximal deformation that can be sustained by a rotating
neutron star with a crystalline colour superconducting quark core. Our results
suggest that current gravitational-wave data from LIGO have already reached the
level where a detection would have been possible over a wide range of the
poorly constrained QCD parameters. This leads to the non-trivial conclusion
that compact objects \emph{do not} contain maximally strained colour
crystalline cores drawn from this range of parameter space. We discuss the
uncertainties associated with our simple model and how it can be improved in
the future.
