  We derive photometric, structural and dynamical evolution-related parameters
of five as yet unstudied low-contrast open clusters located in the third
quadrant using 2MASS data. The target clusters are Czernik 31, Czernik 32,
Haffner 9, Haffner 11 and Trumpler 13. We apply a statistical field-star
decontamination procedure to infer on the intrinsic CMD morphology which is
critical for such low-contrast objects. Consequently, it became possible to
derive accurate reddening, age, distance from the Sun and Galactocentric
distance for the five clusters. In the structural and luminosity/mass-function
analyses we apply a colour-magnitude filter which encompasses the cluster
evolutionary CMD sequences and excludes stars with discrepant colours. Using
this procedure we derive core and limiting radii, mass function slope, total
mass, mass density and relaxation time. We derive ages in the range 140 -- 1
100 Myr, Galactocentric distances within 7.7 -- 11.4 kpc, and total masses
within 360--2 900 \ms. Reflecting large-scale mass segregation, the MF slope in
the core is significantly flatter than that in the halo of the five clusters.
Although some of the present clusters are relatively younger than the Gyr-old
clusters, they present evidence of advanced dynamical evolution. This kind of
study has become possible because of the photometric uniformity and spatial
coverage of 2MASS which allows a proper subtraction of the field-star
contamination on the target CMDs. The present study indicates that low-contrast
clusters can be studied with 2MASS, particularly after field-star subtraction,
which is important since most of the unstudied open clusters belong to this
class.
