Comprehensive photometric investigation was carried out to the early K-type contact binary - IL Cnc .
A few light curves from both ground-based telescopes and the Kepler space telescope were obtained ( or downloaded ) and then analyzed in detail .
They are mostly found to be asymmetric and there are even continuously changing O ’ Connell effect in the light curves from Kepler K2 data , suggesting the system to be highly active .
Using the Wilson-Devinney code ( version 2013 ) , photometric solutions were derived and then compared .
It is found that the calculation of the mass ratio is easily affected by the spot settings .
Combining the radial velocities determined from LAMOST median resolution spectral data , the mass ratio of the binary components is found to be M _ { 2 } / M _ { 1 } = 1.76 \pm 0.05 .
The components are in shallow contact ( f \sim 9 \% ) and have a temperature difference about T _ { 2 } - T _ { 1 } = -280 \pm 20 K. The system is demonstrated to be W-subtype , which may be a common feature of K-type contact binaries .
The masses of the binary components were estimated to be M _ { 1 } \sim 0.51 M _ { \solar } and M _ { 2 } \sim 0.90 M _ { \solar } .
The values are in good agreement with that deduced from the parallax data of Gaia .
The results suggest that the primary component lacks luminosity compared with the zero main sequence .
The H \alpha spectral line of the primary component is found to be peculiar .
Combining newly determined minimum light times with those collected from literature , the orbital period of IL Cnc is studied .
It is found that the ( O - C ) s of the primary minima show sinusoidal variation while the secondary do not .
The oscillation is more likely to be caused by the starspot activities .
Yet this assumption needs more data to support .