  The origin of the 6.67 hr period X-ray source, 1E161348-5055, in the young
supernova remnant RCW 103 is puzzling. We propose that it may be the descendant
of a Thorne-Zytkow Object (TZO). A TZO may at its formation have a rapidly
spinning neutron star as a core, and a slowly rotating envelope. We found that
the core could be braked quickly to an extremely long spin period by the
coupling between its magnetic field and the envelope, and that the envelope
could be disrupted by some powerful bursts or exhausted via stellar wind. If
the envelope is disrupted after the core has spun down, the core will become an
extremely long-period compact object, with a slow proper motion speed,
surrounded by a supernova-remnant-like shell. These features all agree with the
observations of 1E161348-5055. TZOs are expected to have produced extraordinary
high abundances of lithium and rapid proton process elements that would remain
in the remnants and could be used to test this scenario.
