Highly–resolution optical spectra of the optical component of the IR–source IRAS 01005+7910 are used to determine the spectral type of its central star , B1.5 \pm 0.3 , identify the spectral features , and analyze their profile and radial velocity variations .
The systemic velocity V _ { sys } = -50.5 km s ^ { -1 } is determined from the positions of the symmetric and stable profiles of the forbidden [ N I ] , [ N II ] , [ O I ] , [ S II ] , and [ Fe II ] emission lines .
The presence of the [ N II ] and [ S II ] forbidden emissions indicates the onset of the ionization of the circumstellar envelope and the fact that the star is very close to undergoing the planetary nebula stage .
The broad range of heliocentric radial velocity V _ { r } estimates based on the core lines , which amounts to about 34 km s ^ { -1 } , is partly due to the deformations of the profiles caused by variable emissions .
The variations of the V _ { r } in the line wings are smaller , about 23 km s ^ { -1 } , and may be due to pulsations and/or hidden binarity of the star .
The deformations of the profiles of complex absorption–emission lines may result from variations of their absorption components caused by the variations of the geometry and kinematics in the wind base .
The H \alpha lines exhibit P Cyg III type wind profiles .
Deviations of the wind from spherical symmetry are shown to be small .
The relatively low wind velocity ( 27–74 km s ^ { -1 } from different observations ) and the strong intensity of the red emission ( it exceeds the continuum level by up to a factor of seven ) are typical for hypergiants rather than the classical supergiants .
IRAS 01005 is an example of spectral mimicry of a low mass post-AGB star masquerading as a massive hypergiant .