Observation of the unusual Be-X-ray transient A0538-66 in outburst

A0538-66 is a Be transient system containing a neutron star whose pulse period of 69 ms was measured in 1980. The outbursts have a wide range of durations from a few hours to ~14 days. The accretion mechanism proposed to explain the temporal behaviour of A0538-66 is mainly based on gated mechanisms. In these models, the high dynamic range of the source is explained with the onset of a propeller effect which stops the direct accretion. This mechanism predicts a magnetic field of 1e11 G which has never been observed. The main aims of this proposed observation is to measure the neutron star magnetic field, which is still unknown, and its current pulse period, to determine the pulse period derivative.