Program: GN-2014A-Q-86

With this proposal we aim to complete a survey we have been carrying out of GMOS spectroscopy of a sample of WR stars to look for signs of the presence in the wind of large-scale structures named Corotating Intereaction Regions (CIRs). With 2 spectra per star, we are able to identify stars showing large-scale emisison excesses on emission lines, which we associate with potential CIR variables. To complete our initial survey, we only need to obtain one spectrum for 9 stars. For the stars that we have already identified as viable candidates from the spectra in hand, we wish to collect a slightly larger number of spectra (5) in order to be able to evaluate the level of line-flux variability and confirm them as CIR variables. Now that we have greatly reduced the number of stars of interest, this can be achieved with a relatively modest observing time. With this new list of CIR candidates in hand, we will be able to carry out the extensive follow-up observations rquired to detect the period of the variability for several WR stars and measure their rotation rate. With more CIR candidates identified we will also gain more insight into the origin of the perturbation at the base of the wind which are responsable for these large-scale asymetric winds.