Evidence for synchronisation of

The Gaia DR3 catalogue includes line-broadening measurements (<ns0:monospace>vbroad</ns0:monospace>) for 10 387 eclipsing binaries. In this study, we focus on a subset of 977 short-period main-sequence sources with primary radii in the range of [1.25, 3] R⊙, effective temperatures between 5600 and 8000 K, orbital periods from 0.3 to 3 days, <ns0:monospace>vbroad</ns0:monospace> measurements between 30 and 300 km/s, eclipse depth ratios below 0.7 and |e cos ω| < 0.1. Our analysis reveals a clear inverse correlation between the derived <ns0:monospace>vbroad</ns0:monospace> values and the orbital periods of these systems, consistent with tidal synchronisation and spin–orbit alignment. We further compare the Gaia <ns0:monospace>vbroad</ns0:monospace> results with the expected rotational velocities of the primaries of these binaries, given the radius estimate of these stars. We find that the <ns0:monospace>vbroad</ns0:monospace> measurements are generally consistent with the expected rotational broadening, except for a systematic lower factor of approximately 10%.