  We report on three X-ray observations of Nova LMC 2000 with XMM at 17, 51 and
294 days after the maximum, respectively. X-ray spectral fits show a concordant
decrease of the absorbing column and the X-ray luminosity. No supersoft X-ray
emission is detected. The mass of the ejected shell is determined to be (less
than) 7.5*E-5 msun. Though data are sparse, one interesting correlation becomes
visible: sources with a long-duration supersoft X-ray phase have shorter
orbital periods than those with short or no supersoft X-ray phase. This can be
understood considering that (i) enough matter has to be accreted in order to
ignite the H burning, and (ii) that H burning ceases when the mass of the
remaining material (after shell ejection and burning) drops below a certain
limit under which the temperature at the bottom of the envelope is too low for
the shell burning to compensate the energy loss from the surface.
