2005A&A...429..625D

We present the first high-resolution spectra of the WUMa contact binary V524 Mon. The spectra of the two components are very similar, resembling a G5 and a K0. We find the radial velocities and rotational velocities consistent with corotation. We estimate the radii and the masses and derive a mass ratio M₂/M₁=2.1. We confirm that V524Mon is a W-type contact system, likely enclosed in a common convective envelope, as found by Samec & Loflin (2003IBVS.5404....1S). We do not find evidence for the expected level of emission in the chromospheric CaII H and K lines, neither Hα, indicating that the magnetic activity is much weaker than expected or that other processes are hampering chromospheric emission.