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   PR # 11021
     In recent ROSAT observations (RASS) of Planetary Nebulae, the exist-
    ense of X-ray halo around central hot star up to several arcmin was
    shown. The size of the halo is corresponding to 0.3pc. Observed
    spectrum shows extremely high temperature which cannot be explained
    by contribution from hot central star. Small size of shell indicate
    large extinction and high temperature of Nova activity of PNe. We'd
    like to propose the observations of hidden X-ray activities of PNe
    using ASCA instruments.




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