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1.
The first complete CCD light curves of the eclipsing binary system V370 Cygni have been obtained in the B, V, R and I filters
during 5 consecutive nights in 2005 at Kryoneri Observatory, Greece. These curves were analyzed with the Wilson–Devinney program
in order to determine the geometrical and physical parameters of the system. The analysis indicates a semi-detached configuration
and a mildly evolved state of the system.
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《New Astronomy》2021
The first reliable radial velocity curves for RZ Tau have been obtained. Combined with new light curve (LC) data, simultaneous Roche-based light curve analyses have been carried out using the 2003 version of the Wilson-Devinney code. New values for the masses and radii have been obtained: M1 = 1.53 (4) Mʘ, M2 = 0.57 (2) Mʘ, and R1 = 1.50 (4) Rʘ, R2 = 0.99 (2) Rʘ. Although there is a multitude of spectral classifications listed in the literature, the classification of F0 from Struve et al. (1950) is shown to be the most reliable. On the basis of the latter, the most likely luminosities are L1 = 4.97 (44) Lʘ and L2 = 2.11 (19) Lʘ. Additional modelling was carried out using the same RV data, but with LC data (binned and unbinned) from Binnendijk (1963); the results were substantially the same except that they favoured slightly later spectral sub-classes. 相似文献
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《Chinese Astronomy and Astrophysics》1982,6(3):199-204
The 1978 photoeletric observations of the late type close binary RZ Dra were reanalyzed with the Wilson and Devinney approach. Photometric parameters were determined (in Tab. 1.). The system is found to be semi-detached where the less massive component fills its Roche surface, whereas the other component almost does so. The configuration of the system is shown in Fig. 1. The absolute dimensions of the system are found to be M1 = 0.61M⊙, . Both components appear to be overluminous and oversized for their masses and spectral types. Its evolutionary stage is also discussed. The variability in the brightness of the primary mlnimum(Fig. 4) indicates mass loss from the vicinity of L2, which would be mainly responsible for the long-term decrease in its period. 相似文献
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In this study we present photometric observations of the eclipsing binary KR Cyg made in 1999 and 2000. The observations of
the eclipsing binary KR Cyg have been carried out in B, V and R colours at the Ege University Observatory. A new seasonal
light curves are presented. New times of minima and ephemerides are given. Based on a statistical analysis of the times of
minima obtained by photoelectric photometry, the orbital period of the system is found to be constant. The photometric mass
ratio of the system is well determined. The corresponding light curves were analyzed by the Wilson-Devinney code.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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UBV light curves obtained in 1975 for both components of ADS 9537 are presented. These light curves and the light curve of BV Dra by Yamasaki have been solved for geometrical parameters using the synthesis method under two hypotheses explaining theW-subclass light curves: (1) temperature excess of the less massive components; (2) spots on the more massive components; the results are very similar. Because of the poor determinacy of the solutions, mass-ratios have been assumed:q=0.8 for BV Dra and a range inq for BW Dra; our solutions suggest preference for smallerq in the latter system. We compare both variables and conclude that they follow the Main Sequence dependences. We give also a bried discussion of the existing information on other contact binaries in multiple (visual) systems: the contact binaries seem to follow the same statistical distributions for occurrence in multiples as found for detached binaries but severe selection effects limit detectability for multiple systems with wide orbits having semi-axes below 100 a.u.On leave from the Warsaw University Observatory.Visiting Astronomer, Kitt Peak National Observatory which is operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. 相似文献
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T. Iijima 《Astrophysics and Space Science》1987,131(1-2):759-762
The mass accretion process onto the hot component of AG Dra and its explosive phenomena are discussed. The hot component seems to be a massive white dwarf (M>1 M). The mass accretion rate is estimated to be about 10–7M/year. Many properties of the explosive phenomena agree with those of mild hydrogen flashes expected from this rapid mass accretion.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986. 相似文献
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《New Astronomy》2016
The present study is an analysis of V-band CCD observations of new W UMa contact binary OQ Dra. To carry out the analysis, Primary and secondary minimum were obtained and new epoch was calculated. The computed period of system was 0.33967 day. Light curve analysis was performed using Binary Maker 3 and PHOEBE that uses the latest Wilson–Devinney code. We obtained photometric mass ratio of qptm = 0.55.O’Connell effect also was seen in the fitted model. Finally, the best model was achieved by introducing 2 spots on each component. 相似文献
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The eclipsing binary system AI Dra reveals changes of its orbital period. These variations could be described as a result
of orbiting the eclipsing pair around a common center of mass with two unseen companions with the periods about 18 and 43 years
together with a steady period increase. Fourteen new minima observations were carried out by the authors. 相似文献
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E. Soydugan F. Soydugan C. Ibanolu A. Frasca O. Demircan M. C. Akan 《Astronomische Nachrichten》2006,327(9):905-911
We present new BV photometry and spectroscopic observations of RZ Cassiopeiae. The light and radial velocity curves were formed by the new observations which have been analyzed simultaneously by using theWilson‐Dewinney code. The non‐synchronous rotational velocity v 1 sin i = 76 ± 6 km s–1, deduced for the primary component from the new spectroscopic observations, was also incorporated in the analysis. A time‐series analysis of the residual light curves revealed the multi‐periodic pulsations of the primary component of RZ Cas. The main peak in the frequency spectrum was observed at about 64.197 c d–1 in both B and V bands. The pulsational constant was calculated to be 0.0116 days. This value corresponds to high overtones (n ∼ 6) of non‐radial mode oscillations.We find significant changes in the pulsational amplitude of the primary component from year to year. The peak‐to‐peak pulsational amplitude of the main frequency displays a decrease from 0.m013 in 2000 to 0.m002 in 2001 and thereafter we have found an increase again in the amplitude to 0.m01 in the year 2002. We propose the mass transfer from the cool secondary to the pulsating primary as a possible explanation for such remarkable changes in the pulsational behavior of the primary component. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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H. Sana E. Gosset † Y. Nazé † G. Rauw † N. Linder †‡ 《Monthly notices of the Royal Astronomical Society》2008,386(1):447-460
We present the results of a long-term high-resolution spectroscopy campaign on the O-type stars in NGC 6231. We revise the spectral classification and multiplicity of these objects and we constrain the fundamental properties of the O-star population. Almost three quarters of the O-type stars in the cluster are members of a binary system. The minimum binary fraction is 0.63, with half the O-type binaries having an orbital period of the order of a few days. The eccentricities of all the short-period binaries are revised downward, and henceforth match a normal period–eccentricity distribution. The mass ratio distribution shows a large preference for O + OB binaries, ruling out the possibility that, in NGC 6231, the companion of an O-type star is randomly drawn from a standard initial mass function. Obtained from a complete and homogeneous population of O-type stars, our conclusions provide interesting observational constraints to be confronted with the formation and early evolution theories of O-stars. 相似文献
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The photoelectric light curves of TW Dra obtained by Baglow (1952) and by Walter (1978) have been re-analysed by means of Wood's (1972) model in order to obtain accurate photometric elements. Significantly different elements have resulted from the two sets of observations, but more confidence can be given to the elements deduced from Walter's (1978) data. Radii and luminosities have been computed with the aid of Popper's (1978) new values for masses.TW Dra is confirmed to be a typical sd-system, having a distinctly oversized and overluminous secondary. Interestingly, the primary appears to be slightly more luminous than expected for a Main-Sequences star, in agreement with theoretical predictions for present primaries of massexchange binaries systems. 相似文献