All the sources within 15′ from the known centre of Be17 are shown in grey, the proper-motion-selected members are shown in blue, and the BSS candidates from Ahumada & Lapasset (2007) are shown in orange. Top: proper motion of the stars. Middle: spatial distribution of the stars. Bottom: CMD for the stars where the isochrone, shown with a black solid line, corresponds to the adopted age and metallicity of Be17. The photometric errors are shown on the right in black. The errors in magnitude are negligible.