103 research outputs found

    Nearby low-mass triple system GJ795

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    We report the results of our optical speckle-interferometric observations of the nearby triple system GJ795 performed with the 6-m BTA telescope with diffraction-limited angular resolution. The three components of the system were optically resolved for the first time. Position measurements allowed us to determine the elements of the inner orbit of the triple system. We use the measured magnitude differences to estimate the absolute magnitudes and spectral types of the components of the triple: MVAaM_{V}^{Aa}=7.31±\pm0.08, MVAbM_{V}^{Ab}=8.66±\pm0.10, MVBM_{V}^{B}=8.42±\pm0.10, SpAaSp_{Aa} ≈\approxK5, SpAbSp_{Ab} ≈\approxK9, SpBSp_{B} ≈\approxK8. The total mass of the system is equal to ÎŁMAB\Sigma\mathcal{M}_{AB}=1.69±0.27M⊙\pm0.27\mathcal{M}_{\odot}. We show GJ795 to be a hierarchical triple system which satisfies the empirical stability criteria.Comment: 6 pages, 2 figures, published in Astrophysical Bulleti

    Speckle Interferometry of Nearby Multiple Stars. IV. Measurements in 2004 and New Orbits

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    The results of speckle interferometric observations of 104 binary and 6 triple stars performed at the BTA 6 m telescope in 2004 October are presented. Nearby low-mass stars are mostly observed for the program, among which 59 there are new binaries recently discovered by the Hipparcos astrometric satellite. Concurrently with the diffraction-limited position measurements we obtained 154 brightness ratio measurements of binary and multiple star components in different bands of the visible spectrum. New, first-resolved binaries are the symbiotic star CH Cyg with a weak companion at 0.043'' separation and the pair of red dwarfs, GJ 913 = HIP 118212. In addition, we derived the orbital parameters for two interferometric systems: the CN-giant pair HD 210211 = HIP 109281 (P=10.7 yr) and the G2V-K2V binary GJ 9830 = HIP 116259 (P=15.7 yr).Comment: 11 pages, 2 figures, accepted to Astrophysical Bulleti

    GJ 900: A new hierarchical system with low-mass components

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    Speckle interferometric observations made with the 6 m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences in 2000 revealed the triple nature of the nearby (πHip=51.80±1.74\pi_{Hip}=51.80\pm1.74 mas) low-mass young (≈200\approx200 Myr) star GJ 900. The configuration of the triple system allowed it to be dynamically unstable. Differential photometry performed from 2000 through 2004 yielded II- and KK-band absolute magnitudes and spectral types for the components to be IAI_{A}=6.66±\pm0.08, IBI_{B}=9.15±\pm0.11, ICI_{C}=10.08±\pm0.26, KAK_{A}=4.84±\pm0.08, KBK_{B}=6.76±\pm0.20, KCK_{C}=7.39±\pm0.31, SpASp_{A}≈\approxK5--K7, SpBSp_{B}≈\approxM3--M4, SpCSp_{C}≈\approxM5--M6. The ``mass--luminosity'' relation is used to estimate the individual masses of the components: MA\mathcal{M}_{A}≈0.64M⊙\approx0.64\mathcal{M}_{\odot}, MB\mathcal{M}_{B}≈0.21M⊙\approx0.21\mathcal{M}_{\odot}, MC\mathcal{M}_{C}≈0.13M⊙\approx0.13\mathcal{M}_{\odot}. From the observations of the components relative motion in the period 2000--2006, we conclude that GJ 900 is a hierarchical triple star with the possible orbital periods PA−BC_{A-BC}≈\approx80 yrs and PBC_{BC}≈\approx20 yrs. An analysis of the 2MASS images of the region around GJ 900 leads us to suggest that the system can include other very-low-mass components.Comment: 7 pages, 5 figure

    Study of the influence of topical application of Persantine on the condition of the oral mucosa of rats under the conditions of systemic action of pathogenic factors

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    Balega M. I., Schneider S. A., Borodach V. A., Tkachenko E. K. Study of the influence of topical application of Persantine on the condition of the oral mucosa of rats under the conditions of systemic action of pathogenic factors. Journal of Education, Health and Sport. 2018;8(9):1778-1784. eISNN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.1467938 http://ojs.ukw.edu.pl/index.php/johs/article/view/6211 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part b item 1223 (26/01/2017). 1223 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Author(s) 2018; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 17.09.2018. Revised: 24.09.2018. Accepted: 27.09.2018. Study of the influence of topical application of Persantine on the condition of the oral mucosa of rats under the conditions of systemic action of pathogenic factors 1M. I. Balega, Ph.D.; 2S. A. Schneider, Dr.Sc.; 1V. A. Borodach, Ph.D.; 2E. K. Tkachenko, Ph.D. 1Uzhgorod National University, Ukraine 2State Establishment “The Institute of Stomatology and Maxillo-Facial Surgery National Academy of Medical Science of Ukraine” Аbstract Purpose of the study. The study of the protective role of the рersantine when topically applied to the condition of the oral mucosa of rats under conditions of systemic exposure to the fluorine toxicant against the background of polyphenolic insufficiency. Materials and methods. The experiment was conducted on 21 white rat-male 2 months ages that were distributed over 7 animals in a group. The 1st group is intact, the rats were fed on the vivarium diet. In the second group (control oh) in rat bespolifenolnogo background ration was prepared 5 times in week 5% fluorouracil solution per os at a dose of 12.5 mg / kg body weight of rats. The third group, under the combined effect of fluorouracil under the conditions of a bespolyphenol regimen, received topically as a part of a gel, рersantine in a dose of 0.5 mg / kg 5 times a week. Gel - freshly prepared 7.5% potato starch was applied topically to the oral mucosa of the rats. Results and conclusions. introduced against the background of the genotoxicant of fluorouracil in the alimentary deficiency of plant components , manifested in the oral mucosa antioxidant and anti-inflammatory effects. Under the influence of the chimes, the state of the vessels of the microvasculature was normalized due to a significant decrease in edema - the packing density of the vessels and the coefficient of preservation of their lumen increased. There are data on the effect of various toxicants with a lack of plant food components on the occurrence of dental pathology [3]. Keywords: Curantil, local application, pathogenic factors, oral mucosa, rats

    Speckle Interferometry of Metal-Poor Stars in the Solar Neighborhood. I

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    We report the results of speckle-interferometric observations of 109 high proper-motion metal-poor stars made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolve eight objects -- G102-20, G191-55, BD+19∘^\circ~1185A, G89-14, G87-45, G87-47, G111-38, and G114-25 -- into individual components and we are the first to astrometrically resolve seven of these stars. New resolved systems included two triple (G111-38, G87-47) and one quadruple (G89-14) star. The ratio of single-to-binary-to-triple-to-quadruple systems among the stars of our sample is equal to 71:28:6:1.Comment: 8 pages, 4 figures, accepted to Astrophysical Bulleti

    PHASES High Precision Differential Astrometry of delta Equulei

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    delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. It is widely used to calibrate and constrain theoretical models of the physics of stars. We report 27 high precision differential astrometry measurements of delta Equulei from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES). The median size of the minor axes of the uncertainty ellipses for these measurements is 26 micro-arcseconds. These data are combined with previously published radial velocity data and other previously published differential astrometry measurements using other techniques to produce a combined model for the system orbit. The distance to the system is determined to within a twentieth of a parsec and the component masses are determined at the level of a percent. The constraints on masses and distance are limited by the precisions of the radial velocity data; we outline plans improve this deficiency and discuss the outlook for further study of this binary.Comment: Accepted by AJ. Complete versions of tables 2-7 now available at http://stuff.mit.edu/~matthew1/deltaEquTables/ (removed from astroph server

    Physical and dynamical parameters of the multiple system HD 222326

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    We present the results of our study of the physical and dynamical parameters of the multiple system HD 222326. A new method for determining the individual radial velocities of components in wide binary and multiple systems in the case of small radial-velocity differences (ΎV r the FWHMfor the line profiles) is suggested and tested for both model systems and the binary HD 10009. This testing yielded the component radial velocities V r 1,2 for HD 10009, enabling us to derive the center-of mass velocity, V γ, for the first time. We determined the radial velocities of the components of HD 222326 from high-resolution spectra, and refined the orbital parameters of the subsystems using speckle-interferometric observations. A combined spectroscopic and speckle interferometric analysis enabled us to find the positions of the components in the spectral type-luminosity diagram and to estimate their masses. It is likely that the components are all in various evolutionary stages after leaving the main sequence. We analyzed the dynamical evolution of the system using numerical modeling in the gravitational three-body problem and the known stability criteria for triple systems. The system is probably stable on time scales of at least 106 years. The presence of a fourth component in the system is also suggested. © 2008 Pleiades Publishing, Ltd

    A quasi-time-dependent radiative transfer model of OH104.9+2.4

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    We investigate the pulsation-phase dependent properties of the circumstellar dust shell (CDS) of the OH/IR star OH104.9+2.4 based on radiative transfer modeling (RTM) using the code DUSTY. Our previous study concerning simultaneous modeling of the spectral energy distribution (SED) and near-infrared (NIR) visibilities (Riechers et al. 2004) has now been extended by means of a more detailed analysis of the pulsation-phase dependence of the model parameters of OH104.9+2.4. In order to investigate the temporal variation in the spatial structure of the CDS, additional NIR speckle interferometric observations in the K' band were carried out with the 6 m telescope of the Special Astrophysical Observatory (SAO). At a wavelength of 2.12 micron the diffraction-limited resolution of 74 mas was attained. Several key parameters of our previous best-fitting model had to be adjusted in order to be consistent with the newly extended amount of observational data. It was found that a simple rescaling of the bolometric flux F_bol is not sufficient to take the variability of the source into account, as the change in optical depth over a full pulsation cycle is rather high. On the other hand, the impact of a change in effective temperature T_eff on SED and visibility is rather small. However, observations, as well as models for other AGB stars, show the necessity of including a variation of T_eff with pulsation phase in the radiative transfer models. Therefore, our new best-fitting model accounts for these changes.Comment: 7 pages, including 5 postscript figures and 3 tables. Published in Astronomy and Astrophysics. (v1: accepted version; v2: published version, minor grammatical changes

    Physical parameters and dynamical properties of the multiple system Îč UMa (ADS 7114)

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    We analyze the physical parameters, orbital elements, and dynamic stability of the multiple system Îč UMa (HD 76644 = ADS 7114). We have used the positions from the WDS catalog and our own observations on the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and the 1.5-m Russian-Turkish Telescope (Antalya, Turkey). We have obtained more precise orbital parameters of the subsystems, and spectral types, absolute magnitudes, and masses of the components. The primary has Sp = F0 V-IV, M = 1.7 ± 0.1M ⊙, T eff = 7260 ± 70 K, and log g = 4.30 ± 0.07. The companion in the close Aa subsystem is most likely a white dwarf with a mass of approximately 1.0 ± 0. 3M ⊙. The spectral types and masses of the components in the BC subsystem are M3V, M4V and 0.35 ± 0.05M ⊙, 0.30 ± 0.05M ⊙, respectively. The total mass is 3.4 ± 0.4M ⊙. The Aa subsystem probably has an orbital period of 4470 d = 12.2 y and an eccentricity of approximately 0.6. The outer subsystem seems to have a period of approximately 2084 yrs and an eccentricity of approximately 0.9. We have carried out simulations using the stability criteria and shown that for all possible variations in the component parameters, the multiple system is unstable on a time scale of less than 10 6 years with a probability exceeding 0.98. Possible reasons for this instability are discussed. © 2012 Pleiades Publishing, Ltd
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