Search Publications
Features of the Residual Velocity Ellipsoid of Hot Subdwarfs from the Gaia DR2 Catalog
Bobylev, V. V.; Bajkova, A. T.
The evolution of the parameters of the residual velocity ellipsoid of hot subdwarfs (HSDs) with their position relative to the Galactic plane is traced, using the HSDs selected by Geier et al. from the Gaia DR2 catalog. Parameters of the Galactic rotation are determined for two ∣ z∣ zones. These are used to estimate the gradient of the circular ro…
Influence of Digital Noise on Interpretation of a Transit Light Curve
Abubekerov, M. K.; Gostev, N. Yu.
The algorithms often used for the interpretation of light curves, such as the frequently applied JKTEBOP algorithm, have limited accuracy, which causes rounding errors, and hence a non-physical contribution to the residuals (digital noise). The transit light curve of the binary HD 209458 is used as an example to demonstrate the need to take into a…
Spectroscopy of Globular Clusters in the Spheroidal Dwarf Galaxy IKN
Sharina, M. E.; Shimansky, V. V.
Moderate resolution spectra of four globular clusters in the dwarf spheroidal galaxy IKN obtained with the 6-m telescope of the Special Astrophysical Observatory have been used to determine the radial velocities, ages, and metallicities of the clusters, and also to derive the first approximate estimates of the abundances of Mg, Ca, and C. Cross-co…
Surface Photometry of Proplyds in the Vicinity of θ 1 Ori C
Ismailov, N. Z.; Mamedkhanova, G. B.
Results of studies of the surface-brightness distributions of a group of young stellar objects located within 16″ of the star θ 1 Ori C are presented. Isophotes around each proplyd are constructed using violet, red, and near-infrared images. No regularity in the sizes of the diametral cross sections of the proplyds in the various photom…
Prospects for Strongly Lensed Supernovae Behind Hubble Frontier Fields Galaxy Clusters with the James Webb Space Telescope
Goobar, A.; Mahler, G.; Kawamata, R. +3 more
Measuring time delays from strongly lensed supernovae (SNe) is emerging as a novel and independent tool for estimating the Hubble constant ( H 0). This is very important given the recent discord in the value of H 0) from two methods that probe different distance ranges. The success of this technique will rely of our ability t…
Kinematics of OB Associations and the First Data from the Gaia Satellite
Dambis, A. K.; Mel'nik, A. M.
The first data release from the Gaia mission (Gaia DR1) is used to study kinematics of OB associations. The mean velocity dispersion in 18 OB associations containing at least 10 stars with proper motions from the TGAS catalog is 3.9 km/s. The contribution of binary systems to the velocity dispersions in OB associations is, on average, 1.2 km/s. Ex…
Studies of Modern Star Catalogs Based on Photoelectric Observations of Lunar Occultations of Stars
Churkin, K. O.; Andreev, A. O.; Nefedyev, Yu. A. +2 more
An important area of investigation in astronomy is the relationship between fundamental and dynamical coordinate systems. Valuable material for such studies is provided by photoelectric occultation observations of stars by the Moon, which can provide high precision of detecting rapidly occurring processes and have been carried out over a long time…
The Nature of Variations in Anomalies of the Chemical Composition of the Solar Corona with the 11-Year Cycle
Pipin, V. V.; Tomozov, V. M.
Evidence that the distribution of the abundances of admixtures with low first-ionization potentials (FIP < 10 eV) in the lower solar corona could be associated with the typology of the largescale magnetic field is presented. Solar observations show an enhancement in the abundances of elements with low FIPs compared to elements with high FIPs (&…
"Carte du Ciel" Catalogs and Their Importance for Modern Astrometry
Sementsov, V. N.
Astronomical catalogs created as a result of the "Carte du Ciel" project are considered, including the work of K.V. Kuimov in this area, its methodological importance, and perspectives in the GAIA era. This paper is based on a presentation made at the conference "Modern Astrometry 2017," dedicated to the memory of K.V. Kuimov (Sternberg Astronomic…
Kinematic Groups in the Corona of the Ursa Majoris Flow Indicated by Gaia Data
Vereshchagin, S. V.; Chupina, N. V.; Postnikova, E. S.
The internal kinematics of the Ursa Majoris stellar flow is considered. The details of the flow structure are considered, and new candidate members are searched for using high-precision Gaia DR1 TGAS data. The flow structure is studied using apex diagrams, which have been shown to be effective in studies of open clusters. To select member-stars of…