  Both high precision CCD photometric and H$alpha$ line studies are presented
for an overcontact binary ASAS J082243+1927.0. The light curve exhibits a total
eclipse at secondary minima along with an O'Connell effect. The light curve was
modeled using the Wilson Devinney code and the best solution provides the mass
ratio q = 0.106 and fill-out factor f = 72%. These parameters indicate that the
system is a low mass ratio overcontact binary with a high degree of geometrical
contact. The H alpha line equivalent width varied at different phases and it is
found that the line is possibly filled-in at secondary minima. From a small
sample of overcontact binaries, we found a correlation between the orbital
period and H alpha line equivalent width of the primary component. Based on a
sample of high filling factor and low mass ratio contact binaries, a mass ratio
cut-off is observed at q = 0.085 in mass ratio - period plane. It was observed
that below q $\le$ 0.085, period decreases with an increase in q and above it,
period increases as the mass ratio increases. Interestingly, the observed mass
ratio cut-off value lies close to the critical mass ratio range as predicted in
the literature. The observational evidence of the cut-off of the mass ratio and
its variation with orbital period are discussed in terms of mass transfer and
angular momentum loss. Based on the results, we suggest that, ASAS
J082243+1927.0 is at the verge of merger, eventually forming a fast rotating
star.
