We report on the analysis of 8 years of MAssive Compact Halo Objects (MACHO) data for the source RX J0520.5-6932. A regular period of 24.4 days has been confirmed, however this is manifest almost entirely in the red part of the spectrum. A major outburst, lasting approximately 200 days, was observed which increased the apparent brightness of the object by approximately 0.15 magnitudes without significantly altering its V-R colour index. This outburst was also seen in X-ray data. The evidence from this analysis points to the identification of this object as a Be/X-ray binary with a periodically variable circumstellar disk and a very early optical counterpart.
@article{arxiv.astro-ph/0401537,
title = {A major outburst from the X-ray binary RX J0520.5-6932},
author = {W. R. T. Edge and M. J. Coe and J. L. Galache and A. B. Hill},
journal= {arXiv preprint arXiv:astro-ph/0401537},
year = {2009}
}