Spectroscopic Diagnostics of Symbiotic Stars III. Radial Velocity Analyses of HBV 475

We present highly resolved spectroscopic data of HBV 475 (= V 1329 Cyg) in the optical region, which have been obtained during the past 10 years at the Okayama Astrophysical Observatory. We analyzed line profiles of Hα , Hγ , He II lambda 4686, [O III] lambda 5007, and [Fe VII] lambda 6086 using Gaussian de-convolution method, and investigated the variation of individual components of the profiles as a function of the orbital phase. We revised the mass function obtained from the orbital elements of the hot star as f_h(M) ~ 1.2 +/- 0.3 MO . It differs considerably from previously published values, which were larger than 20 MO . However, our new mass function is more reasonable for a symbiotic system consisting of a red giant and a hot star, which is currently presumed to be a white dwarf. Finally, we suggest a descriptive model of line-emitting regions in the HBV 475 binary, which explains the basic variation in the line profiles and agrees with the main features of the HST image.