title: Revised physical elements of the astrophysically important O9.5+O9.5V eclipsing binary system Y Cygni
abstract: Context. Rapid advancements in light-curve and radial-velocity curve modelling, as well as improvements in the accuracy of observations, allow more stringent tests of the theory of stellar evolution. Binaries with rapid apsidal advance are particularly useful in this respect since the internal structure of the stars can also be tested.
journal: Astronomy and Astrophysics