共查询到20条相似文献，搜索用时 62 毫秒
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T. Pribulla S.M. Rucinski D.W. Latham S.N. Quinn M. Siwak J.M. Matthews R. Kuschnig J.F. Rowe D.B. Guenther A.F.J. Moffat D. Sasselov G.A.H. Walker W.W. Weiss 《Astronomische Nachrichten》2010,331(4):397-411
Sixteen new eclipsing binaries have been discovered by the MOST satellite among guide stars used to point its telescope in various fields. Several previously known eclipsing binaries were also observed by MOST with unprecedented quality. Among the objects we discuss in more detail are short‐period eclipsing binaries with eccentric orbits in young open clusters: V578 Mon in NGC 2244 and HD 47934 in NGC 2264. Long nearly‐continuous photometric runs made it possible to discover three long‐period eclipsing binaries with orbits seen almost edge‐on: HD 45972 with P = 28.1 days and two systems (GSC 154 1247 and GSC 2141 526) with P > 25 days. The high precision of the satellite data led to discoveries of binaries with very shallow eclipses (e.g., HD 46180 with A = 0.016 mag, and HD 47934 with A = 0.025 mag). Ground‐based spectroscopy to support the space‐based photometry was used to refine the models of several of the systems (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The catalogue of the light curve solutions of contact binary stars was updated. Based on the catalogue data we call the attention to a remarkable gap in the temperature distribution of contact binaries which remained unexplained. The absolute dimensions of the components were calculated in a reliable way. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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M. Scardia J.-L. Prieur L. Pansecchi R. W. Argyle M. Sala M. Ghigo L. Koechlin E. Aristidi 《Monthly notices of the Royal Astronomical Society》2006,367(3):1170-1180
We present relative astrometric measurements of visual binaries taken during the second semester of 2004 with the Pupil Interferometry Speckle camera and Coronagraph (PISCO) at the 1-m Zeiss telescope of the Brera Astronomical Observatory, in Merate, Italy. We performed 207 new observations of 194 objects with angular separations in the range 0.1–4.0 arcsec and an accuracy better than ∼0.01 arcsec. Our sample contains orbital couples as well as binaries whose motion is still uncertain. Our purpose is to improve the accuracy of the orbits and constrain the masses of the components.
Those measurements show that the orbit of ADS 15115 needs to be revised; we propose a new orbit for this object. 相似文献
Those measurements show that the orbit of ADS 15115 needs to be revised; we propose a new orbit for this object. 相似文献
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Z. Bozkurt Ö. L. De&#;irmenci 《Monthly notices of the Royal Astronomical Society》2007,379(1):370-378
Binary systems showing both apsidal motion and light travel time (LTT) effects which cause orbital period changes in close binaries were studied. 15 triple systems showing apsidal motion were found by searching the literature, and a table including the important parameters of these systems was constructed. Six of the systems given in this table were selected and observed photometrically. Existence of both apsidal motion and LTT effects in all selected systems was investigated by means of the analysis of their eclipse times. The mean observed internal structure constants, log = k 2,obs , and contributions to the apsidal motion from the theory of General Relativity and the third/fourth bodies were calculated. The masses of the third/fourth bodies and some characteristics of their orbits were also calculated. 相似文献
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Nikolaos Georgakarakos 《Monthly notices of the Royal Astronomical Society》2009,392(3):1253-1263
In a series of papers, we developed a technique for estimating the inner eccentricity in hierarchical triple systems, with the inner orbit being initially circular. However, for certain combinations of the masses and the orbital elements, the secular part of the solution failed. In this paper, we derive a new solution for the secular part of the inner eccentricity, which corrects the previous weakness. The derivation applies to hierarchical triple systems with coplanar and initially circular orbits. The new formula is tested numerically by integrating the full equations of motion for systems with mass ratios from 10−3 to 103 . We also present more numerical results for short-term eccentricity evolution, in order to get a better picture of the behaviour of the inner eccentricity. 相似文献
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A. K. Pandey S. Sharma K. Ogura 《Monthly notices of the Royal Astronomical Society》2006,373(1):255-262
We present colour–magnitude diagrams of open clusters, located in the range 112° < l < 252° , manifesting stellar populations in the background of clusters. Some of the populations are found to be located beyond the Perseus arm and may be the part of the Norma-Cygnus (outer) arm. The outer arm seems to be continued from l ∼ 120° to ∼235°. The background populations follow the downward warp of the Galactic plane around l ∼ 240° . 相似文献
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Following a brief history of measurement of eclipsing binary mass ratios from light curves, we show that photometric mass
ratios for overcontact and semi-detached binaries are reliable because the relative stellar radii, R/a, are accurately measured and not, as commonly claimed, because of information in the light variation outside eclipse. We
explore the accuracy of photometric mass ratios by solving synthetic data of typical precisions for a semi-detached and an
overcontact binary for orbital inclinations from 89∘ down into the partial eclipse range. 相似文献
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Mark T. Reynolds Paul J. Callanan Edward L. Robinson Cynthia S. Froning 《Monthly notices of the Royal Astronomical Society》2008,387(2):788-796
The most widely used means of measuring the mass of black holes in Galactic binaries – specifically the X-ray novae – involves both radial velocity measurements of the secondary star, and photometric measurements of its ellipsoidal variability. The latter is important in constraining the inclination and mass ratio, and requires as direct a measure of the flux of the secondary as possible. Up to now, such measurements have been preferentially carried out in the near-infrared (NIR: 1–2.5 μm ), where the flux from the cooler secondary is expected to dominate over that from the accretion disc. However, here we present evidence of a significant non-stellar contribution to the NIR flux in many of those quiescent X-ray novae that are thought to contain a black hole primary. We discuss origins of this excess and the effect of such contamination on Galactic black hole mass measurements. 相似文献
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A. M. Cherepashchuk R. A. Sunyaev K. A. Postnov E. A. Antokhina S. V. Molkov 《Monthly notices of the Royal Astronomical Society》2009,397(1):479-487
The analysis of hard X-ray INTEGRAL observations (2003–2008) of superaccreting Galactic microquasar SS433 at precessional phases of the source with the maximum disc opening angle is carried out. It is found that the shape and width of the primary X-ray eclipse are strongly variable, suggesting additional absorption in dense stellar wind and gas outflows from the optical A7I component and the wind–wind collision region. The independence of the observed hard X-ray spectrum on the accretion disc precessional phase suggests that hard X-ray emission (20–100 keV) is formed in an extended, hot, quasi-isothermal corona, probably heated by interaction of relativistic jet with inhomogeneous wind outflow from the precessing supercritical accretion disc. A joint modelling of X-ray eclipsing and precessional hard X-ray variability of SS433 revealed by INTEGRAL by a geometrical model suggests the binary mass ratio q = mx / m v ≃ 0.25–0.5. The absolute minimum of joint orbital and precessional χ2 residuals is reached at q ≃ 0.3 . The found binary mass ratio range allows us to explain the substantial precessional variability of the minimum brightness at the middle of the primary optical eclipse. For the mass function of the optical star f v = 0.268 M⊙ as derived from Hillwig & Gies data, the obtained value of q ≃ 0.3 yields the masses of the components mx ≃ 5.3 M⊙ , m v ≃ 17.7 M⊙ , confirming the black hole nature of the compact object in SS433. 相似文献
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Slavek M. Rucinski Wenxian Lu 《Monthly notices of the Royal Astronomical Society》2000,315(3):587-594
Radial velocity data for both components of W Crv are presented. In spite of providing full radial-velocity information, the new data are not sufficient to establish the configuration of this important system because of large seasonal light curve perturbations, which prevent a combined light curve/radial-velocity solution. It is noted that the primary minimum is free of photometric perturbations, and this property may help to explain the elusive source of these perturbations. Photometrically, the system appears to be a contact binary with poor or absent energy exchange, but such an explanation – in view of the presence of light curve perturbations – is no more plausible than any one of the semi-detached configurations, with either the more-massive or less-massive components filling the associated Roche lobes. Lengthening of the orbital period and the size of the less-massive component above its main-sequence value, both suggest that the system is the shortest-period (0.388 d) known Algol with non-degenerate components. 相似文献
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We use the method introduced by Karami & Mohebi (2007), and Karami & Teimoorinia (2007) which enable us to derive the orbital
parameters of the spectroscopic binary stars by the nonlinear least squares of observed vs. curve fitting (o-c). Using the measured experimental data for radial velocities of the four double-lined spectroscopic binary
systems PV Pup, HD 141929, EE Cet and V921 Her, we find both the orbital and the combined spectroscopic elements of these
systems. Our numerical results are in good agreement with those obtained using the method of Lehmann-Filhés. 相似文献
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K. Karami R. Mohebi 《中国天文和天体物理学报》2007,7(4):558-564
We introduce a new method to derive the orbital parameters of spectroscopic bi-nary stars by nonlinear least squares of (o-c). Using the measured radial velocity data of the four double lined spectroscopic binary systems, AI Phe, GM Dra, HD 93917 and V502 Oph, we derived both the orbital and combined spectroscopic elements of these systems. Our numerical results are in good agreement with the those obtained using the method of Lehmann-Filhe's. 相似文献