Instability in the system of the distant post-AGB star LS III+52 24
  (IRAS 22023+5249)
  The optical spectra of the B-supergiant LS III+52 24 (IRAS 22023+5249)
obtained at the 6-meter telescope BTA with a resolution R$\ge$60000 in
2010-2021 revealed signs of wind variability and velocity stratification in the
extended atmosphere. The H$\alpha$ and H$\beta$ lines have a P Cyg type
profile; their wind absorption changes position in the range from $-270$ to
$-290$ km/s. The intensity of the H$\alpha$ emission reaches record values with
respect to the local continuum: I/Icont $\approx$70. The stationary radial
velocity according to the positions of symmetric forbidden emissions and
permitted metal emissions was taken as the systemic velocity
Vsys=$-149.6\pm$0.6 km/s. Based on the positions of absorptions of NII and OII
ions, a time variability of the radial velocity in the range from $-127.2$ to
$-178.3$ km/s was found for the first time for this star. This variability
indicates the possible presence of a companion and/or atmospheric pulsations.
The change of the oxygen triplet profile OI 7775 A due to the occurrence of
unstable emission was registered. The set of interstellar absorptions of the
NaI D-lines profile in the range from $-10.0$ to $-167.2$ km/s is formed in the
Local Arm and subsequent arms of the Galaxy. The distance to the star,
d$\ge$5.3 kpc, combined with the high systemic velocity, indicates that the
star is located in the Galaxy beyond the Scutum-Crux arm.
