English

On the evolutionary status of high-latitude variable V534 Lyr

Solar and Stellar Astrophysics 2018-04-04 v1

Abstract

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 Hα\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 Vsys125\approx-125 km/s (V(lsr)105\approx-105 km/s). The distance estimate of d\approx6 kpc for the star leads us to its absolute magnitude of Mv5.3m\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 Δ\DeltaVr=20÷\div50 km/s. A combination of the parameters: reduced metallicity [Met/H]=0.28_{\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.

Keywords

Cite

@article{arxiv.1802.06615,
  title  = {On the evolutionary status of high-latitude variable V534 Lyr},
  author = {V. G. Klochkova and E. G. Sendzikas and E. L. Chentsov},
  journal= {arXiv preprint arXiv:1802.06615},
  year   = {2018}
}

Comments

21 pages, 7 figures, 4 tables