Search Publications
Interpretation of the Transit Light Curve in the Presence of Principal Main Minimum with Allowance for the Eccentricity of the Transit (Planet) Orbit
Abubekerov, M. K.; Gostev, N. Yu.
Using a high-precision algorithm for interpreting transit light curves in a model of a classical eclipsing binary star-exoplanet system, we studied the possibility of determining the system parameters in the absence of a priori knowledge of the orbital eccentricity. It was shown that it is impossible to determine the exact value of the eccentricit…
Determining the Structure of the Atmosphere Exoplanet HD 189733b Based on Multicolor Photometric Transit Observations
Bekesov, E. V.
In this paper, we analyze and interpret light curves obtained by observing with the HST telescope the transit of exoplanet HD 189733b across the disk of the star. Observations are carried out in a wide wavelength range of 5500–10 500 Å, which makes it possible to identify the relation between the wavelength and the data obtained during the interpr…
Modeling of the Exoplanet HAT-P-11b Magnetosphere
Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.
The magnetospheric model of the HAT-P-11b magnetic field has been constructed based on the available data on the magnetic field of the star HAT-P-11 and its closest exoplanet HAT-P-11b, as well as the information on the stellar wind in this system. It has been shown how the magnitude and orientation of the interplanetary magnetic field control the…
Effect of the Eccentricity of the Planet's Orbit on the Limb Darkening Coefficients of the Eclipsed Star
Cherepashchuk, A. M.; Bekesov, E. V.
It is shown that the introduction of a small orbital eccentricity into the model of a binary system with an exoplanet, which is allowed by errors in determining the radial velocities of the eclipsed star, makes possible to significantly reduce and even eliminate the difference in the wavelength dependences between the observed and theoretical valu…
Investigation of the Effect of the Errors of Limb Darkening Coefficients on the Geometric Parameters of a Binary System with an Exoplanet
Abubekerov, M. K.; Gostev, N. Yu.
Based on the observed light curves of Kepler-5, Kepler-6, Kepler-7, HD 209458, a search was made for the geometric parameters of a binary system with an exoplanet for different values of the limb darkening coefficients of the parent star. It is shown that for the observed light curves with relative accuracy ${{10}^{{ - 4}}}{-} {{10}^{{ - 5}}}$, an…
Minimally Modified Gravity Fitting Planck Data Better Than ΛCDM
Pookkillath, M. C.
Here we present cosmology of a class of Minimally Modified Gravity theory dubbed as $f(H)$ theory. After introducing a concrete model for the free function, we find that this cosmological model fits Planck data better than $Λ $CDM.
How We Can Account for Type Ia Supernova Environment in Cosmological Analysis
Pruzhinskaya, M. V.; Pauna, N.; Novinskaya, A. K. +1 more
Among the other types of supernovae, Type Ia Supernovae (SNe Ia) have less luminosity dispersion at maximum light and show higher optical luminosities. These properties allow to use them as cosmological distance indicators that led to the discovery of the accelerating expansion of the Universe. However, even after the luminosity correction for str…
Chemical Composition of Globular Clusters of Milky Way Subsystems from Gaia DR2 Data
Bobylev, V. V.; Bajkova, A. T.; Korchagin, V. I. +1 more
Results of a study of the kinematic and chemical properties of globular clusters of the Milky Way based on data from the Gaia DR2 catalog and meaurements with the Hubble Space Telescope are presented. A new method for dividing globular clusters into Galatic subsystems based on the elements of their Galactic orbits is proposed. Samples of globular …
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…