******************************************************
   PR # 12176
     We proposed to study for the first time the spectral evolution of X-
    ray pulsar OAO1657-415 from the eclipse, through the eclipse egress,
    to relatively unobscured state. Discovered only recently by BATSE,
    the 10.4 days orbital period and eclipse prove conclusively that the
    source is a classic eclipsing massive X-ray binary pulsar,one of only
    seven known.Interestingly, its derived characteristics, its luminoty,
    Po - Ps relation suggest that this system is in transition between a
    wind and/or disk driven accretion. ASCA will be an excellent instru-
    ment to test the nature of the accretion, to probe the circumstellar
    material and to study in detail the behavior of the iron line through
    the eclipse.

 ******************************************************