Abstract

We present the first results of a comprehensive photometric O-star survey performedwith a robotic twin refractor at the Universittssternwarte Bochum located near CerroArmazones in Chile. For three high-mass stars, namely Pismis24-1, CPD-518946 andHD319702, we determined the period through the Lafler-Kinman algorithm and modelthe light curves within the framework of the Roche geometry.For Pismis24-1, a previously known eclipsing binary, we provide first light curvesand determined a photometric period of 2.36 days together with an orbital inclination of61.8o. The best-fitting model solution to the light curves suggest a detached configuration.With a primary temperature ofT1= 42520 K we obtain the temperature of the secondarycomponent asT2= 41500 K.