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   PR # 12177
    We propose a near periastron ASCA observation of the system with the
    pulsar PSR B1259-63 orbiting around a massive Be companion.We expect
    unpulsed X-ray emission to be  produced at the shock region where the
    pulsar wind interacts with the Be-star mass outflow.The nature and a-
    mount of unpulsed shock emission depend on the size of the shock reg-
    ion, the local magnetic field,and the pulsar wind characteristics.We
    expect that as the pulsar approaches periastron, the shock radiation
    flux will increase and be detectable by ASCA;accretion may also occur
    .We have calculated that the periastron passage will occur on January
    9th, 1994. Because of the long  orbital period of PSR B1259-63,the
    sole opportunity for ASCA to observe this system near periastron
   could be during the AO1 period
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