Mass is the fundamental parameter on which the evolution and the physical
properties of a star at a given time depend
directly. The mass of a star, its radius,
effective temperature and abundances can only be accurately measured for
double-lined
eclipsing binaries with well determined light and radial velocity curves.
For late-type stars these fundamental quantities are poorly defined. The
current calibrations in the mass range 
are based on
only a few
stars. New and more accurate determinations of
masses, radii, temperatures and abundances are thus needed for late-type
stars. With this aim, we have undertaken a 6 year monitoring program of six
binary systems classified in the literature as main sequence late-type stars
and obtained good photometric uvby and H
light curves for three
of them during 16 observing campaigns.
CR Cas is a detached binary system which was included in the
photometric monitoring program of low mass
eclipsing binaries due to its classifications as spectral type G5 by
Leung & Scheneider (1977). The time of minimum is JD 2440526.279 and the
period
is 2.840147 days
(Danielkiewicz-Krośniak & Kurpińska-Winiarska
1994).
Lacy (1992) observed CR Cas as a good candidate for determination
of accurate absolute dimensions and obtained
and 
from three photometric
points.
In this paper we present the first uvby light curves
for CR Cas. A few H observations were also performed. Mean
values for the comparison stars and binary system at different orbital phases
are given.
We also present the decoupling of the contribution of both components to
the combined light, and their photometric analysis.
A preliminary analysis of the uvby photometry, with data from the two first campaigns, suggested that the system is a highly reddened early-type binary (Clement et al. 1993). The posterior careful analysis with the data presented in this paper gives the same result. Spectroscopic observations show the presence of He I lines, confirming this conclusion (Popper, private communication).