Type IIP Supernovae ( SNe ) are expected to arise from Red Supergiant stars ( RSGs ) .
These stars have observed mass-loss rates that span more than two orders of magnitude , from < 10 ^ { -6 } \mbox { $M _ { \odot } $ } yr ^ { -1 } to almost 10 ^ { -4 } \mbox { $M _ { \odot } $ } yr ^ { -1 } .
Thermal bremsstrahlung X-ray emission from at least some IIP ’ s should reflect the larger end of the high mass-loss rates .
Strangely , no IIP SNe are seen where the X-ray luminosity is large enough to suggest mass-loss rates greater than about 10 ^ { -5 } \mbox { $M _ { \odot } $ } yr ^ { -1 } .
We investigate if this could be due to absorption of the X-ray emission .
After carefully studying all the various aspects , we conclude that absorption would not be large enough to prevent us from having detected X-ray emission from high mass-loss rate IIP ’ s .
This leads us to the conclusion that there may be an upper limit of \sim 10 ^ { -5 } \mbox { $M _ { \odot } $ } yr ^ { -1 } to the mass-loss rate of Type IIP progenitors , and therefore to the luminosity of RSGs that explode to form Type IIPs .
This is turn suggests an upper limit of \la 19 \mbox { $M _ { \odot } $ } for the progenitor mass of a Type IIP SN .
This limit is close to that obtained by direct detection of IIP progenitors , as well as that suggested by recent stellar evolution calculations .
Although the statistics need to be improved , many current indicators support the notion that RSGs above \sim 19 \mbox { $M _ { \odot } $ } do not explode to form Type IIP SNe .