The study of resonant variability observed in the massive LMC system BI 108

The LMC star BI 108 is photometrically variable with the unique light curve: Two strong periods are present in a strict 3:2 resonance, staying coherent over several observing seasons. A spectroscopic data collected at VLT/UVES reveals unexpected and still not fully understood behavior of the system, that has not been observed in any other early-type multiple systems.