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Based on the high resolution spectral monitoring conducted at the 6-m BTA telescope, we study the optical spectrum of the high-latitude variable V534 Lyr. Heliocentric radial velocities Vr corresponding to the positions of all metal absorption components, as well as the NaI D and H$\alpha$ lines were measured during all the observational dates. The analysis of the velocity field examining the lines of various nature revealed a low-amplitude variability of Vr based on the lines with a high excitation potential, which are formed in deep layers of the stellar atmosphere, and allowed to estimate the systemic velocity of Vsys$\approx-125$ km/s (V(lsr)$\approx-105$ km/s). The distance estimate of d$\approx$6 kpc for the star leads us to its absolute magnitude of Mv$\approx -5.3^{m}$, what corresponds to the MK spectral classification. The previously undetected for this star spectral phenomenon was revealed: at certain times a splitting of the profiles of low-excited absorptions is observed, reaching $\Delta$Vr=20$\div$50 km/s. A combination of the parameters: reduced metallicity [Met/H]$_{\odot}=-0.28$, increased nitrogen abundance [N/Fe]=+1.10, large spatial velocity, high luminosity, a strong variability of the emission-absorption profiles of HI lines, splitting of metal absorptions at different observation moments and the variability of the velocity field in the atmosphere allow us to consider V534 Lyr as a pulsating star in the instability band near the HB and belonging to the thick disk of our Galaxy., Comment: 21 pages, 7 figures, 4 tables

Based on the high resolution spectral monitoring conducted at the 6-m BTA telescope, we study the optical spectrum of the high-latitude variable V534 Lyr. Heliocentric radial velocities Vr corresponding to the positions of all metal absorption components, as well as the NaI D and H$\alpha$ lines were measured during all the observational dates. The analysis of the velocity field examining the lines of various nature revealed a low-amplitude variability of Vr based on the lines with a high excitation potential, which are formed in deep layers of the stellar atmosphere, and allowed to estimate the systemic velocity of Vsys$\approx-125$ km/s (V(lsr)$\approx-105$ km/s). The distance estimate of d$\approx$6 kpc for the star leads us to its absolute magnitude of Mv$\approx -5.3^{m}$, what corresponds to the MK spectral classification. The previously undetected for this star spectral phenomenon was revealed: at certain times a splitting of the profiles of low-excited absorptions is observed, reaching $\Delta$Vr=20$\div$50 km/s. A combination of the parameters: reduced metallicity [Met/H]$_{\odot}=-0.28$, increased nitrogen abundance [N/Fe]=+1.10, large spatial velocity, high luminosity, a strong variability of the emission-absorption profiles of HI lines, splitting of metal absorptions at different observation moments and the variability of the velocity field in the atmosphere allow us to consider V534 Lyr as a pulsating star in the instability band near the HB and belonging to the thick disk of our Galaxy., Comment: 21 pages, 7 figures, 4 tables

We study a pulsating variable post-AGB star V534 Lyr = HD172324 based on five high resolution spectra (R = 60 000) obtained with the NES echelle spectrograph of the 6--meter Russian telescope (BTA) in 2010 and 2013. Using the atmosphere modeling method and the Kurucz model set, we obtained the effective temperature T$_{\rm eff}$ = 10500 K, surface gravity log g = 2.5, and microturbulent velocity ${\rm \xi_t}$=4.0 km/s. The underabundance of the iron group elements ${\rm [Met/H]_{\odot} = -0.50}$ was detected. This fact in combination with high spatial velocity indicates that V534 Lyr does not belong to the disk population. The radial velocity gradient in the V534 Lyr atmosphere is minimum: differential shifts of lines are close to measurement errors The spectral class A0 Iab corresponds to the distance to V534 Lyr, d$\approx$6 kpc., Comment: 4 pages, 1 figure

We study a pulsating variable post-AGB star V534 Lyr = HD172324 based on five high resolution spectra (R = 60 000) obtained with the NES echelle spectrograph of the 6--meter Russian telescope (BTA) in 2010 and 2013. Using the atmosphere modeling method and the Kurucz model set, we obtained the effective temperature T$_{\rm eff}$ = 10500 K, surface gravity log g = 2.5, and microturbulent velocity ${\rm \xi_t}$=4.0 km/s. The underabundance of the iron group elements ${\rm [Met/H]_{\odot} = -0.50}$ was detected. This fact in combination with high spatial velocity indicates that V534 Lyr does not belong to the disk population. The radial velocity gradient in the V534 Lyr atmosphere is minimum: differential shifts of lines are close to measurement errors The spectral class A0 Iab corresponds to the distance to V534 Lyr, d$\approx$6 kpc., Comment: 4 pages, 1 figure

Based on high-spectral-resolution observations (R=60000) performed with the 6-m BTA telescope in combination with the echelle spectrograph NES, we have studied the optical spectra of three A-type supergiants: a peculiar supergiant 3 Pup, a post-AGB star BD+48 1220, and a massive $\alpha$ Cyg, which belong to essentially different stages of evolution. A spectral atlas for these stars is prepared in the wavelength interval of 3920 to 6720 \AA., Comment: 56 pages, 2 tables, 10 figures

Based on high-spectral-resolution observations (R=60000) performed with the 6-m BTA telescope in combination with the echelle spectrograph NES, we have studied the optical spectra of three A-type supergiants: a peculiar supergiant 3 Pup, a post-AGB star BD+48 1220, and a massive $\alpha$ Cyg, which belong to essentially different stages of evolution. A spectral atlas for these stars is prepared in the wavelength interval of 3920 to 6720 \AA., Comment: 56 pages, 2 tables, 10 figures

Highly-resolution optical spectra of the optical component of the IR-source IRAS01005+7910 are used to determine the spectral type of its central star, B1.5$ \pm $0.3, identify the spectral features, and analyze their profile and radial velocity variations. The systemic velocity Vsys =$-50.5$ km/s is determined from the positions of the symmetric and stable profiles of the forbidden [NI], [NII], [OI], [SII], and [FeII] emission lines. The presence of the [NII] and [SII] 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 Vr estimates based on the core lines, which amounts to about 34 km/s, is partly due to the deformations of the profiles caused by variable emissions. The variations of the Vr in the line wings are smaller, about 23 km/s, 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$\div$74 km/s 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. IRAS01005 +7910 is an example of spectral mimicry of a low mass post-AGB star masquerading as a massive hypergiant., Comment: 23 pages, 11 figures, 2 tables

Highly-resolution optical spectra of the optical component of the IR-source IRAS01005+7910 are used to determine the spectral type of its central star, B1.5$ \pm $0.3, identify the spectral features, and analyze their profile and radial velocity variations. The systemic velocity Vsys =$-50.5$ km/s is determined from the positions of the symmetric and stable profiles of the forbidden [NI], [NII], [OI], [SII], and [FeII] emission lines. The presence of the [NII] and [SII] 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 Vr estimates based on the core lines, which amounts to about 34 km/s, is partly due to the deformations of the profiles caused by variable emissions. The variations of the Vr in the line wings are smaller, about 23 km/s, 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$\div$74 km/s 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. IRAS01005 +7910 is an example of spectral mimicry of a low mass post-AGB star masquerading as a massive hypergiant., Comment: 23 pages, 11 figures, 2 tables