Comparison of synthetic V broad-band linear polarization from ESPaDOnS and literature values. a) The abscissa is the degree of polarization (P) measured using ESPaDOnS. The ordinate is the literature value (P_lit). The dashed line represents P_lit = P. b) The residual (P_lit − P). The gray zone indicates a one-sigma dispersion around the mean value: 0 ± 0.23% (dashed line). c) The abscissa is the polarization position angle (PA) measured using ESPaDOnS. The ordinate is the literature value (PA_lit). The dashed line represents PA_lit = PA. The black dots are objects with P> 0.5% and crosses with P< 0.5%. The PA variable HD 144668 is labeled. d) The residual (PA_lit − PA) only for objects with P> 0.5%. The gray zone indicates a one-sigma dispersion around the mean value: −33 ± 43.