2002A&A...392..143K

We present a study of the high-resolution spectroscopic data for the proto-planetary nebula candidate IRAS 01005+7910. For the first time a careful spectral line identification is carried out, and a significant variability of the optical spectrum is detected. We found absorption lines of CII/III, NII, OII, AlIII, SiIII, and MgII (λ4481Å), as well as emission lines of Siii and [FeII]. Both absorption and emission components are present in the Balmer lines, NaI resonance D_1,2 lines, HeI, and FeIII lines. The HeI line profiles vary from straight to inverse P Cyg-type on a timescale of days to months. The resonance NaI lines show 5 absorption components at a resolution of R=60000. Additionally, the NaI D₂ line exhibits a variable emission component with a width comparable to that of the Balmer line emission components. Using the model atmospheres method within the LTE-approximation, the effective temperature (T_eff∼21500K), the metallicity [Fe/H]_☉=-0.31, and the ratio C/O>1 is reported. Finally, we suggest that IRAS 01005+7910 is a carbon-rich post-AGB star with a luminosity log(L/L_☉)=3.6 at a distance about 3kpc.