  We proposed alternative explanation to the rapid cooling of neutron star in
Cas A. It is suggested that the star is experiencing the recovery period
following the r-mode heating process,assuming the star is differentially
rotating. Like the neutron-superfluidity-triggering model, our model predicts
the rapid cooling will continue for several decades. However, the behavior of
the two models has slight differences, and they might be distinguished by
observations in the near future.
