Search Publications
The outburst of the X-ray nova GRS 1739-278 in September 2016
Sunyaev, R. A.; Grebenev, S. A.; Burenin, R. A. +3 more
During the scanning observations of the Galactic center region in late August-September 2016 we detected a new (third) outburst of the historical X-ray nova GRS 1739-278, a presumed black hole in a low-mass X-ray binary. This was reported in the Astronomer's Telegrams (Mereminskiy et al. 2016). In this paper we present the results of INTEGRAL and …
Vertical distribution and kinematics of planetary nebulae in the milky way
Bobylev, V. V.; Bajkova, A. T.
Based on published data, we have produced a sample of planetary nebulae (PNe) that is complete within 2 kpc of the Sun. We have estimated the total number of PNe in the Galaxy from this sample to be 17 000±3000 and determined the vertical scale height of the thin disk based on an exponential density distribution to be 197 ± 10 pc. The next sample …
Properties of the Tycho-2 catalogue from Gaia data release
Tsvetkov, A. S.; Vityazev, V. V.; Petrov, S. D. +2 more
Based on the measurements performed in the first 14 months of Gaia operation, we have solved the problem of obtaining the systematic differences between the stellar positions and proper motions of the TGAS (Tycho-Gaia Astrometric Solution) and Tycho-2 catalogues. By dividing the common stars from the TGAS and Tycho-2 catalogues into three G-magnit…
Vertical distribution and kinematics of protoplanetary nebulae in the galaxy
Bobylev, V. V.; Bajkova, A. T.
The catalogue of protoplanetary nebulae by Vickers et al. has been supplemented with the line-of-sight velocities and proper motions of their central stars from the literature. Based on an exponential density distribution, we have estimated the vertical scale height from objects with an age less than 3 Gyr belonging to the Galactic thin disk (lumi…
Influence of the magnetic field on the density distribution of solar wind protons and cometary ions in the shock layer ahead of cometary ionospheres
Baranov, V. B.; Alexashov, D. B.
The "mass loading" of the solar wind by cometary ions produced by the photoionization of neutral molecules outflowing from the cometary nucleus plays a major role in the interaction of the solar wind with cometary atmospheres. In particular, this process leads to a decrease in the solar wind velocity with a transition from supersonic velocities to…
Sizes of the stellar subsystems of galaxies and intracluster stars in the Virgo cluster.
Tikhonov, N. A.
Stellar photometry for three fields in the Virgo cluster of galaxies has been performed on the basis of archival Hubble Space Telescope ACS/WFC images. The densely populated red giant branches belonging to cluster galaxies are seen on the constructed Hertzsprung-Russell diagrams. The distances to eight galaxies in the Virgo cluster have been deter…
Spectroscopic studies of yellow supergiants in the Cepheid instability strip
Usenko, I. A.
High-resolution spectra of nine yellow nonvariable supergiants (NVSs) located within the canonical Cepheid instability strip from Sandage and Tammann (1969) ( α Aqr, ɛ Leo, µ Per, ω Gem, BD+60 2532, HD 172365, HD 187299, HD 190113, and HD 200102) were taken with the 1-m Zeiss and 6-m BTA telescopes at the Special Astrophysical Observatory of…
Rotation curve and mass distribution in the Galaxy from the velocities of objects at distances up to 200 kpc
Bobylev, V. V.; Bajkova, A. T.
Three three-component (bulge, disk, halo) model Galactic gravitational potentials differing by the expression for the dark matter halo are considered. The central (bulge) and disk components are described by the Miyamoto-Nagai expressions. The Allen-Santillán (I), Wilkinson-Evans (II), and Navarro-Frenk-White (III) models are used to describe the …
Extinction law at a distance up to 25 kpc toward the Galactic poles
Gontcharov, G. A.
Photometry from the Tycho-2, 2MASS, andWISE catalogues for clump and branch giants at a distance up to 25 kpc toward the Galactic poles has allowed the variations of various characteristics of the infrared interstellar extinction law with distance to be analyzed. The results obtained by the extinction law extrapolation method are consistent for di…
Additional spectroscopic redshift measurements for galaxy clusters from the first Planck catalogue
Aghanim, N.; Melnikov, S. S.; Irtuganov, E. N. +10 more
We present the results of spectroscopic redshift measurements for the galaxy clusters from the first all-sky Planck catalogue that have been mostly identified based on the optical observations performed previously by our team (Planck Collaboration 2015a). Data on 13 galaxy clusters at redshifts from z ≈ 0.2 to z ≈ 0.8, including the improved ident…