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 \sim 0.106 and fill-out factor f \sim 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 _ { critical } = 0.085 in mass-ratio – period plane .
It was observed that below q _ { critical } < 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 .