  We present results of 6 years of observations, reduced and analyzed with the
same tools in a systematic way. We report completely new data for 15 objects,
for 5 objects we present a new analysis of previously published results plus
additional data and for 9 objects we present a new analysis of data already
published. Lightcurves, possible rotation periods and photometric amplitudes
are reported for all of them. The photometric variability is smaller than
previously thought: the mean amplitude of our sample is 0.1mag and only around
15% of our sample has a larger variability than 0.15mag. The smaller
variability than previously thought seems to be a bias of previous
observations. We find a very weak trend of faster spinning objects towards
smaller sizes, which appears to be consistent with the fact that the smaller
objects are more collisionally evolved, but could also be a specific feature of
the Centaurs, the smallest objects in our sample. We also find that the smaller
the objects, the larger their amplitude, which is also consistent with the idea
that small objects are more collisionally evolved and thus more deformed.
Average rotation rates from our work are 7.5h for the whole sample, 7.6h for
the TNOs alone and 7.3h for the Centaurs. All of them appear to be somewhat
faster than what one can derive from a compilation of the scientific literature
and our own results. Maxwellian fits to the rotation rate distribution give
mean values of 7.5h (for the whole sample) and 7.3h (for the TNOs only).
Assuming hydrostatic equilibrium we can determine densities from our sample
under the additional assumption that the lightcurves are dominated by shape
effects, which is likely not realistic. The resulting average density is
0.92g/cm^3 which is not far from the density constraint that one can derive
from the apparent spin barrier that we observe.
