  We use R-band CCD linear polarimetry collected for about 12000 background
field stars in 46 fields of view toward the Pipe nebula to investigate the
properties of the polarization across this dark cloud. Based on archival 2MASS
data we estimate that the surveyed areas present total visual extinctions in
the range 0.6 < Av < 4.6. While the observed polarizations show a well ordered
large scale pattern, with polarization vectors almost perpendicularly aligned
to the cloud's long axis, at core scales one see details that are
characteristics of each core. Although many observed stars present degree of
polarization which are unusual for the common interstellar medium, our analysis
suggests that the dust grains constituting the diffuse parts of the Pipe nebula
seem to have the same properties as the normal Galactic interstellar medium.
Estimates of the second-order structure function of the polarization angles
suggest that most of the Pipe nebula is magnetically dominated and that
turbulence is sub-Alvenic. The Pipe nebula is certainly an interesting region
where to investigate the processes prevailing during the initial phases of low
mass stellar formation.
