Three presumably young eclipsing binary systems in the direction of the Cygnus OB1 , OB3 and OB9 associations are studied .
Component spectra are reconstructed and their orbits are determined using light curves and spectra disentangling techniques .
V443 Cyg and V456 Cyg have circular orbits , while the light curve of V2107 Cyg imposes a slightly eccentric orbit ( e = 0.045 \pm 0.03 ) .
V443 Cyg harbours F–type stars , and not young early–A stars as previously suggested in the literature based on photometry solely .
It appears to be situated in the foreground ( distance 0.6 \pm 0.2 kpc ) of the young stellar populations in Cygnus .
V456 Cyg , at a distance of 0.50 \pm 0.03 kpc consists of a slightly metal-weak A–type and an early–F star .
The age of both systems , on or very near to the main sequence , remains uncertain by an order of magnitude .
V2107 Cyg is a more massive system ( 8.9 \pm 2 and 4.5 \pm 1.2 M _ { \odot } ) at 1.5 \pm 0.5 kpc and , also kinematically , a strong candidate-member of Cyg OB1 .
The more massive component is slightly evolved and appears to undergo non-radial \beta~ { } Cep –type pulsations .
The Doppler signal of the secondary is barely detectable .
A more extensive study is important to fix masses more precisely , and an asteroseismological study would then become appropriate .
Nevertheless , the position of the primary in the HR-diagram confines the age already reasonably well to 20 \pm 5 Myr , indicating for Cyg OB1 a similar extent of star formation history as established for Cyg OB2 .