Disentangling the Spectroscopic Signatures of Clumping and Corotating Interaction Regions in the Wolf–Rayet Star WR 6

Abstract Wolf–Rayet (WR) winds exhibit variability driven by small-scale clumping and large-scale corotating interaction regions (CIRs), but their interplay remains uncertain. Archival high-resolution ESPaDOnS spectra of WR 6 were analyzed using wavelet decomposition to isolate variability on different scales. Time variance spectrum diagnostics confirm that clumping contributes 1% variability relative to line intensity, consistent with empirical trends for WR stars. Correlation analysis reveals strong coherence among He ii lines, while the N v λ 4945 and He i λ 5876 lines display weaker or shifted correlations, reflecting differences in their line-formation regions relative to He ii . Models in which CIRs locally suppress clumping demonstrate that if such interactions occur, spectroscopic diagnostics remain inconclusive. These results provide direct evidence that CIRs and clumping can coexist in WR winds.