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47 Result(s)

within I. S. Savanov Remove this filter Astronomy, Astrophysics and Cosmology Remove this filter

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  1. No Access

    Article

    Differential Rotation of Stars in Spectral Class A

    Published data indicate a substantial increase in the differential rotation parameter ∆Ω of stars hotter than 6700 K. By analyzing the shape of the light curves and the presence of a specific set of peaks in t...

    I. S. Savanov, E. S. Kalinicheva, E. S. Dmitrienko in Astrophysics (2020)

  2. No Access

    Article

    Slowly Rotating Ap Stars, Prospects for Observing Them with the Tess Space Mission

    The feasibility of detecting candidate slow-rotating magnetic Ap stars with periods from a few tens of days to several hundred years is considered. The question of the fraction of objects of this kind among al...

    I. S. Savanov in Astrophysics (2020)

  3. No Access

    Article

    The Program Magreg for Determining the Longitudinal Component of Stellar Magnetic Fields from Spectropolarimetric Observations

    The computer program magreg in IDL language has been developed for determining the longitudinal component Bz of the magnetic field of stars. The program has been tested on observations of a number of objects a...

    I. S. Savanov in Astrophysics (2020)

  4. No Access

    Article

    Astrophysical Space Mission Astron-2 for an All-Sky Survey in the Ultraviolet Spectral Domain

    This paper presents the project of the space astrophysical observatory Astron-2 aimed to carry out the all-sky spectral and photometric survey in the ultraviolet spectral region (115–310 nm). The major instrum...

    M. E. Sachkov, I. S. Savanov, B. M. Shustov, A. S. Shugarov… in Solar System Research (2019)

  5. No Access

    Article

    Activity of the Star bScl Observed by the TESS Space Telescope

    The rotational and flare activity of the chemically peculiar star B9.5IIIpHgMnSi βScl is studied using data from the archive of the TESS space mission. Rotational modulation of the brightness is clearly visibl...

    I. S. Savanov in Astrophysics (2019)

  6. No Access

    Article

    Variations in the Brightness Variability Amplitude of A–M Stars

    We study relations of the parameter Rvar (amplitude of the brightness variability, stellar activity indicator) with respect to the effective temperature and the period of rotation of stars belonging to the A–M sp...

    I. S. Savanov in Astrophysical Bulletin (2019)

  7. No Access

    Article

    Activity of the Star ET Dra

    V-band photometric observations of the FK Com type star ET Dra were made at the Zvenigorod observatory (INASAN) during March-April 2018. The new data were used in a solution of the inverse problem of recoverin...

    I. S. Savanov, S. A. Naroenkov, M. A. Nalivkin, E. S. Dmitrienko in Astrophysics (2019)

  8. No Access

    Article

    KIC7739728—A New FK Com-Type Star Candidate

    We present a study of the parameters of objects belonging to a sparsely populated group of FKCom-type stars, as well as a brief review of our earlier studies dedicated to the search for stellar candidates of t...

    I. S. Savanov in Astrophysical Bulletin (2019)

  9. No Access

    Article

    Areas, Lifetimes, and Magnetic Fields of Starspots

    The results of applying a method developed by us for determining the spottedness parameter A to data on the brightness variation of 34030 objects based on observations with the Kepler space telescope are prese...

    I. S. Savanov in Astrophysics (2019)

  10. No Access

    Article

    Brightness Variability of 12 ROTD A-Stars

    The brightness variability of 12 stars of spectral class A which are type ROTD objects is analyzed. The power spectra of these objects contain characteristic features including a amplitude-dominant narrow peak...

    I. S. Savanov, E. S. Dmitrienko in Astrophysics (2019)

  11. No Access

    Article

    On the Differential Rotation of Stars

    We discussmethods for analyzing the observational manifestations of differential rotation (DR). Based on the literary sources and our estimates (for 4 cool dwarfs), a list containing 75 stars was compiled. Usi...

    I. S. Savanov, E. S. Dmitrienko, D. S. Pandei, S. Karmakar in Astrophysical Bulletin (2018)

  12. No Access

    Article

    Long-Term Variability in the Magnetic Field of the Ap Star γ Equ

    New measurements of the longitudinal magnetic field of the Ap star γ Equ obtained with the MSS spectrograph of the 6-m telescope of the SAO RAS in 2002–2018 are present. Analyzing our results together with all...

    I. S. Savanov, I. I. Romanyuk, E. S. Dmitrienko in Astrophysical Bulletin (2018)

  13. No Access

    Article

    Photometric Observations of LO Peg in 2017

    New observations of the ultrafast rotator of the K3 spectral type, the star LO Peg, were carried out using a robotic wide-angle observation system in the Zvenigorod observatory of INASAN in 2017. Temperature-i...

    I. S. Savanov, S. A. Naroenkov, M. A. Nalivkin, V. B. Puzin… in Astrophysical Bulletin (2018)

  14. No Access

    Article

    Spots and activity cycles of the star FKCom—2013–2015 data analysis

    We present an analysis of new photometric and spectropolarimetric observations of a chromospherically active star FKCom. Based on this observational data and the data from the literature sources, applying a co...

    V. B. Puzin, I. S. Savanov, E. S. Dmitrienko, I. I. Romanyuk… in Astrophysical Bulletin (2016)

  15. No Access

    Article

    Parameters of superflares on G-Type stars observed with the Kepler space telescope

    We continued the analysis of 279 G-type stars with superflares (energies in the range of 1033–1036 erg). We calculated the SFL parameter (part of the stellar surface which emits in the flare). The SFL estimates w...

    I. S. Savanov, E. S. Dmitrienko in Astrophysical Bulletin (2016)

  16. No Access

    Article

    Activity and cold spots on the surface of G-type superflare stars

    Based on the high precision photometric observations of the Kepler space telescope, we have investigated the properties of the active regions (cold spots) on the surface of 279 stars of the spectral class G, f...

    I. S. Savanov in Astrophysical Bulletin (2015)

  17. No Access

    Article

    A study of cold spots on the surfaces of stars with planetary systems from the Kepler space telescope data

    Based on the photometric observations obtained with the Kepler telescope, we investigated the properties of the active regions (cold spots) on the surfaces of 737 stars with planetary systems (exoplanets). We ...

    I. S. Savanov in Astrophysical Bulletin (2015)

  18. No Access

    Article

    A study of the magnetic field in FK Com

    We present the results of our new spectropolarimetric observations of FKCom aimed to measure the longitudinal component B z of its magnetic field. The most inte...

    V. B. Puzin, I. S. Savanov, I. I. Romanyuk, E. A. Semenko… in Astrophysical Bulletin (2014)

  19. No Access

    Article

    Vertical Chromium Distribution in the Atmospheres of CP Stars. II. Modeling

    Vertical chromium distributions in the atmospheres of several Ap and Am stars are fitted using detailed modeling of the profiles of CrII lines. The vertical distributions obtained for Ap stars are consistent w...

    I. S. Savanov, O. P. Kochukhov, V. V. Tsymbal in Astrophysics (2001)

  20. No Access

    Article

    Vertical Chromium Distribution in the Atmosphere of a Chemically Peculiar Star. I. Diagnostics

    On the basis of CCD spectrograms obtained with high resolution at the Coudé focus of the 2.6-m telescope of the Crimean Astrophysical Observatory, Cr II lines lying in the wings of the Hβ hydrogen line are inv...

    I. S. Savanov, O. P. Kochukhov, V. V. Tsymbal in Astrophysics (2001)

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