We perform binary stellar evolutionary calculations following the simultaneous evolution of both stars in the system to study a potential progenitor system for the Type IIb supernova 2011dh .
Pre-explosion photometry as well as light-curve modeling have provided constraints on the physical properties of the progenitor system .
Here we present a close binary system that is compatible with such constraints .
The system is formed by stars of solar composition with 16 \mathrm { M _ { \odot } } + 10 \mathrm { M _ { \odot } } on a circular orbit with an initial period of 125 days .
The primary star ends its evolution as a yellow supergiant with a mass of \approx 4 \mathrm { M _ { \odot } } , a final hydrogen content of \approx 3 - 5 \times 10 ^ { -3 } \mathrm { M _ { \odot } } and with an effective temperature and luminosity in agreement with the HST pre-explosion observations of SN 2011dh .
These results are nearly insensitive to the adopted accretion efficiency factor \beta .
At the time of explosion , the companion star has an effective temperature of 22 to 40 thousand Kelvin , depending on the value of \beta , and lies near the zero age main sequence .
Considering the uncertainties in the HST pre-SN photometry the secondary star is only marginally detectable in the bluest observed band .
Close binary systems , as opposed to single stars , provide a natural frame to explain the properties of SN 2011dh .