  Z CMa is a complex binary system, composed of a Herbig Be and an FU Ori star.
The Herbig star is surrounded by a dust cocoon of variable geometry, and the
whole system is surrounded by an infalling envelope. Previous
spectropolarimetric observations have reported a preferred orientation of the
polarization angle, perpendicular to the direction of a large, parsec-sized jet
associated with the Herbig star. The variability in the amount of polarized
light has been associated to changes in the geometry of the dust cocoon that
surrounds the Herbig star. We aim to constrain the properties of Z CMa by means
of imaging polarimetry at optical wavelengths. Using ExPo, a dual-beam imaging
polarimeter which operates at optical wavelengths, we have obtained imaging
(linear) polarimetric data of Z CMa. Our observations were secured during the
return to quiescence after the 2008 outburst. We detect three polarized
features over Z CMa. Two of these features are related to the two jets reported
in this system: the large jet associated to the Herbig star, and the micro-jet
associated to the FU Ori star. Our results suggest that the micro-jet extends
to a distance ten times larger than reported in previous studies. The third
feature suggests the presence of a hole in the dust cocoon that surrounds the
Herbig star of this system. According to our simulations, this hole can produce
a pencil beam of light that we see scattered off the low-density envelope
surrounding the system.
