Radial Velocity Studies of Close Binary Stars. XII.

Radial-velocity measurements and sine-curve fits to the orbital radialvelocity variations are presented for ten close binary systems: OO Aql, CC Com,V345 Gem, XY Leo, AM Leo, V1010 Oph, V2612 Oph, XX Sex, W UMa, and XY UMa. Mostof these binaries have been observed spectroscopically before, but our data areof higher quality and consistency than in the previous studies. While most of the studied eclipsing pairs are contact binaries, V1010 Oph isprobably a detached or semi-detached double-lined binary and XY UMa is adetached, chromospherically active system whose broadening functions clearlyshow well defined and localized dark spots on the primary component. Aparticularly interesting case is XY Leo, which is a member of visuallyunresolved quadruple system composed of a contact binary and a detached,non-eclipsing, active binary with 0.805 days orbital period. V345 Gem and AMLeo are known members of visual binaries. We found faint visual companions atabout 2-3 arcsec from XX Sex and XY UMa.Comment: submitted to AJ, revised version Jan 7, 2007, 6 figures, 4 table