Optical Spectroscopy of RU Cam, a Pulsating Carbon Star

We analysed the high resolution spectra of a RUCam, classified as WVir type star. The atmospheric parameters of RUCam were estimated Teff=5250K and logg=1.0. The hydrogen deficiency of RUCam was not confirmed. The iron abundance, (Fe/H)= 0.37, is close to the solar one. Abundances of most other elements are also close to normal. We found considerable excesses of carbon and ni- trogen: (C/Fe)=+0.98, (N/Fe)=+0.60. The carbon to oxygen ratio is C/O>1. The carbon isotopic abundance ratio is equal to 12 C/ 13 C=4.5. For sodium a moderate overabundance Na/Fe=+0.55 was obtained. For two moments of observations we found close heliocentric velocity values, vr= 21.7 ± 0.8 and 23.1 ± 1.0kms −1 . Both spectra contain a pe- culiar feature - an emission component of NaI doublet which location agrees with the radial velocity from the bulk of metallic lines. For our two observing moments we found no dependence of radial velocities on the formation depth or on excitation energy for metallic lines.