We present first results of a comprehensive photometric O-star survey performed with a robotic twin refractor at the Universitätssternwarte Bochum located near Cerro Armazones in Chile .
For three high-mass stars , namely Pismis 24-1 , CPD -51 \degr 8946 and HD 319702 , we determined the period through the Lafler-Kinman algorithm and model the light curves within the framework of the Roche geometry .
For Pismis 24-1 , a previously known eclipsing binary , we provide first light curves and determined a photometric period of 2.36 days together with an orbital inclination of 61.8 ^ { \circ } .
The best-fitting model solution to the light curves suggest a detached configuration .
With a primary temperature of T _ { 1 } = 42520 K we obtain the temperature of the secondary component as T _ { 2 } = 41500 K. CPD - 51° 8946 is another known eclipsing binary for which we present a revised photometric period of 1.96 days with an orbital inclination of 58.4 ^ { \circ } .
The system has likely a semi-detached configuration and a mass ratio q = M _ { 1 } / M _ { 2 } = 2.8 .
If we adopt a primary temperature of T _ { 1 } = 34550 K we obtain T _ { 2 } = 21500 K for the secondary component .
HD 319702 is a newly discovered eclipsing binary member of the young open cluster NGC 6334 .
The system shows well-defined eclipses favouring a detached configuration with a period of 2.0 days and an orbital inclination of 67.5 ^ { \circ } .
Combining our photometric result with the primary spectral type O8 III ( f ) ( T _ { 1 } = 34000 K ) we derive a temperature of T _ { 2 } = 25200 K for the secondary component .