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   PR # 22117
    Superbubbles are formed by the combined action of stellar winds and  
    supernovae from a central OB association sweeping up the ambient     
    interstellar gas.  Diffuse X-ray emission has been observed from     
    several superbubbles in the Large Magellanic Cloud.  The brightest   
    objects have luminosities exceeding model predictions by at least an 
    order of magnitude; the excess X-ray emission may be caused by hidden
    SNRs hitting the superbubble walls.  The faintest superbubbles       
    detected may be normal, heated predominantly by stellar winds.  We   
    propose to compare the physical conditions in two superbubbles, N44  
    and N11, examples of SNR and stellar wind heating, respectively.     
    ASCA spectroscopy will allow us to determine more accurately the     
   physical parameters of the hot
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