2019AJ....158..118W

We present the results from a combined spectroscopic and photometric in-depth study of the binary system BD+11^o3569 (B4 V + B5 V). Fits to Johnson V, Cousins R_C and I_C photometry, and radial velocities yield an orbital period of 1.49712598 ± 0.00000020 days and an inclination of 82.°93 ± 0.°17. The combined light curves and radial velocity solution give masses and radii of M₁ = 5.259 ± 0.064 M_☉ with M₂ = 4.325 ± 0.040 M_☉ and R₁ = 3.509 ± 0.018 R_☉ with R₂ = 2.570 ± 0.023 R_☉. We find that the system does not match a single age isochrone when derived astrophysical quantities for the components are compared with theoretical stellar models, but are bounded by 32 and 40 Myr isochrones. We estimate a distance to the system of 1130 ± 150 pc, which agrees reasonably with the published Gaia distance.