  X-ray images of some young supernova remnants show bright point sources which
have not been detected in radio, optical and gamma-ray bands. Despite the
similarity of the X-ray spectra of these objects, they show a variety of
temporal properties. Most likely, they are neutron stars whose properties (spin
periods? magnetic fields? environments?) are different from those of radio
and/or gamma-ray pulsars. We present an overview of observational results on
several objects of this class -- the central sources of Cassiopeia A, RX
J0852-4622, RCW 103, Puppis A, and PKS 1209-51/52 -- with emphasis on the
recent Chandra observations.

Astrophysics