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In this paper, high quality spectropolarimetric observations of theWolf-Rayet (WR) Star WR1 (HD4004) obtained with ESPaDOnS at CFHT are presented.All major emission lines present in the spectrum show depolarization in therelative Stokes parameters Q/I and U/I. From the behaviour of the amount ofline depolarization as a function of line strength, the intrinsic continuumlight polarization of WR1 is estimated to be P/I=0.443 \pm 0.028 % with anangle of \theta=-26.2^o.  Although such a level of polarization could in principle be caused by a windflattened by fast rotation, the scenario in which it is a consequence of thepresence in the wind of Corotating Interaction Regions (CIRs) is preferred.This is supported by previous photometric and spectroscopic observationsshowing periodic variations with a period of 16.9 days. This is now the thirdWR star thought to exhibit CIRs in its wind that is found to have linedepolarization. Previous authors have found a strong correlation between linedepolarization and the presence of an ejected nebula, which they interpret as asign that the star has reached the WR phase relatively recently since thenebula are thought to dissipate very fast. In the cases where the presence ofCIRs in the wind is favoured to explain the depolarization across spectrallines, the above mentioned correlation may be indicating that those massivestars have only very recently transited from the previous evolutionary phase tothe WR phase.

Revealing the Asymmetry of the Wind of the Variable Wolf-Rayet Star WR1 (HD4004) Through Spectropolarization