SIMBAD references

New multi-color BVR_cI_c photometric observations are presented for the W UMa type eclipsing binary V1073 Cyg. The multi-color light curve analysis with the Wilson-Devinney procedure yielded the absolute parameters of this system, showing that V1073 Cyg is a shallow contact binary system with a fill-out factor f = 0.124(±0.011). We collected all available times of light minima spanning 119 yr, including CCD data to construct the O - C curve, and performed detailed O - C analysis. The O - C diagram shows that the period change is complex. A long-term continuous decrease and a cyclic variation exist. The period is decreasing at a rate of P = -1.04(±0.18) x 10^–10 d cycle^–1 and, with the period decrease, V1073 Cyg will evolve to the deep contact stage. The cyclic variation with a period of P₃ = 82.7(±3.6) yr and an amplitude of A = 0.028(±0.002) d may be explained by magnetic activity of one or both components or the light travel time effect caused by a distant third companion with M₃ (i' = 90°) = 0.511 M_☉.