Radial Velocity Studies of Close Binary Stars. X.

Radial-velocity measurements and sine-curve fits to the orbital velocityvariations are presented for the ninth set of ten close binary systems: V395And, HS Aqr, V449 Aur, FP Boo, SW Lac, KS Peg, IW Per, V592 Per, TU UMi, FOVir. The first three are very close, possibly detached, early-type binaries andall three require further investigation. Particularly interesting is V395 Andwhose spectral type is as early as B7/8 for a 0.685 day orbit binary. KS Pegand IW Per are single-line binaries, with the former probably hosting a verylow mass star. We have detected a low-mass secondary in an importantsemi-detached system FO Vir at q=0.125+/-0.005. The contact binary FP Boo isalso a very small mass-ratio system, q=0.106+/-0.005. The other contactbinaries in this group are V592 Per, TU UMi and the well known SW Lac. V592 Perand TU UMi have bright tertiary companions; for these binaries, and for V395And, we used a novel technique of the broadening functions arranged into a2-dimensional image in phase. The case of TU UMi turned out intractable evenusing this approach and we have not been able to derive a firm radial velocityorbit for this binary. Three systems of this group were observedspectroscopically before: HS Aqr, SW Lac, KS Peg.Comment: Accepted by AJ, August 2005; 5 figure