The ULX NGC 1313 X-2 : an optical study revealing an interesting
  behavior
  We present a summary of our ongoing efforts to study one of the brightest
ultraluminous X-ray source, NGC 1313 X-2. Despite a large coverage in the
X-rays, much of the information we have about the source and its environment
comes from optical wavelenghts. Here, we report on the properties of the
stellar environment, and the differences in the optical counterpart between our
two observing epochs (2003--2004 and 2007--2008). We summarize our ongoing
program designed to look for radial velocity variations in the optical spectra
and for photometric variability.
