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 V _ { r } corresponding to the positions of all metal absorption components , as well as the Na I 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 V _ { r } 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 V _ { sys } \approx - 125 km s ^ { -1 } ( V _ { lsr } \approx - 105 km s ^ { -1 } ) .
The distance estimate of d \approx 6 kpc for the star leads us to its absolute magnitude of M _ { V } \approx - 5 \aas@@fstack { m } 3 , 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 V _ { r } } = 20 – 50 km s ^ { -1 } .
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 H I lines , splitting of metal absorptions at different times of observations and the variability of the velocity field in the atmosphere allow us to classify V534 Lyr as a pulsating star near the HB and belonging to the thick disk of our Galaxy . Keywords : stars , evolution , post-AGB stars , pulsating stars , optical spectroscopy .