******************************************************                         
    PR # 32028                                                                   
     We propose to use ASCA SIS to observe 7 objects of the tau Sco class        
     of B stars.  These stars show stronger and harder emission than             
     normal B stars, and pose an especially large problem for the wind           
     shock models which are commonly thought to explain X-ray emission           
     from early type stars.  By isolating individual emission lines, ASCA        
     will enable us to derive the temperature distribution of hot plasma         
     in these B stars, and also will allow us to search for time                 
     variability in individual spectral features.  Both variability and          
     temperature distribution are strong discriminants among the competing       
     models, as wind shock simulations predict a large degree of                 
     variability as well as a sharp decline in the amount of hot (10             
    million K) gas relative to coo                                               
  ******************************************************