Search Publications
Physical and Dynamical Parameters of the Triple Stellar System: HIP 109951
Docobo, J. A.; Hussein, A. M.; Mardini, M. K. +5 more
The precise determination of the physical and dynamical parameters of the HIP 109951 triple star system (WDS J22161-0705AB) which is formed by the A, Ba, and Bb components are presented. The binary nature of component B was recently confirmed by studying the radial velocities. The analysis of the system follows Al-Wardat's complex method for analy…
Unity and Diversity of Yellow Hypergiants Family
Klochkova, V. G.
We present the results of long-term spectral monitoring of yellow hypergiants (YHGs) of northern hemisphere with a R ≥ 60 000 resolution. The spectra of these F–G stars of extreme luminosity, compactly located at the top of the Hertzsprung–Russell diagram revealed a variety of spectral features: various types of Hα profile, the presence (or absenc…
Kinematics of Open Star Clusters Based on the Data of the New Version of the "Homogeneous Catalog of Open Cluster Parameters"
Loktin, A. V.; Popova, M. E.
We investigate some aspects of Galactic disc kinematics based on the data on open clusters from the current version of "The Homogeneous Catalog of the Main Parameters of Open Star Clusters" and from Gaia DR2. Based on the radial velocity and proper motion data for the clusters we determine the angular velocity of the Sun in the Galaxy as Ω0
Spectroscopy of Supergiants with Infrared Excess: Results of 1998–2018
Klochkova, V. G.
We shortly summarize here the results of the second stage (1998–2018) of the detailed spectroscopy program of peculiar supergiants identified with galactic infrared sources, performed at the 6-m BTA telescope. The main aspect of the program is a search for the evolutionary variations in the chemical composition of stars, past the AGB stage and the…
Optical Spectrum of Distant OH/IR Star V1648 Aql (IRAS 19386+0155)
Klochkova, V. G.; Tavolzhanskaya, N. S.
We present an optical spectrum of the star V1648 Aql (IRAS19386+0155) obtained at the 6-m SAO RAS telescope with a spectral resolution of R ≥ 60 000. Heliocentric radial velocity was measured from numerous metal absorptions is Vr = 10.18 ± 0.05 km s-1 (VLSR = 18.1 km s-1). We determined the atmospheric, …
CCD Observations and Period Change of the Type ab RR Lyrae Star DV Mon
Dambis, A. K.; Berdnikov, L. N.; Kniazev, A. Yu. +3 more
We took a total of 635 B-, V-, and Ic-band CCD frames for the RRab Lyr type variable DVMon, which has a close bright visual companion with a separation of about 1.9'. Observations were made with the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) using SBIG CCD ST-10XME. For the first time, we obtained…
Long-Term Activity of a Little Known Dwarf Nova DT Octantis
Šimon, V.; Edelmann, H.
We analyze the long-term activity of a little known dwarf nova (DN) DT Oct. We use photographic observations from the Bamberg Observatory (Southern Patrol Photographic Sky Survey), CCD data from ASAS-3 survey, and AAVSO data (both CCD and visual). We determined the recurrence times of the superoutbursts, TCso, and of the normal outburst…
Search for Possibly Evolutionary Linked Globular and Open Clusters
Bobylev, V. V.; Bajkova, A. T.
Based on a large sample of 133 Galactic globular clusters we obtained a new estimate of the frequency of globular-cluster impacts onto the Galactic plane, which we found to be equal to three events per 1 Myr. Our computations involving new kinematical data do not support the well-known hypothesis about the possible origin of the open cluster Steph…
SEROB1A Association in DR2 GAIA Epoch
Chentsov, E. L.
In the light of new astrometric and available spectroscopic data, the structure and kinematics of the SerOB1A association are discussed and the issue of correcting its boundaries is put.