首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The eclipsing binary NN Vir is a short period system showing an EW-type light curve. Photometric observations of NN Vir were done by Gomez–Ferrellad and Garcia–Melendo (1997) at Esteve Duran Observatory. The first spectroscopic observations of this system were obtained by Rucinski and Lu (1999). The radial velocity and light curves analysis was made with the latest version of the Wilson program (1998), and the geometric and physical elements of the system are derived. From the simultaneous solutions of the system, we determined the masses and radii of the components: 1.89 M ⊙ and 1.65 R ⊙ for the primary component; 0.93 M ⊙ and 1.23 R ⊙ for the secondary component. We estimated effective temperatures of 7030 K for the primary and 6977 K for the secondary component.  相似文献   

2.
We present the results of our investigation of the geometrical and physical parameters of the W UMa‐type binary V404 Peg from analysis of CCD (BVRI) light curves and radial velocity data. The photometric data were obtained during 2010 at Ankara University Observatory (AUO). Light and radial velocity observations were analyzed simultaneously by using the well‐known Wilson‐Devinney (2007 revision) code to obtain absolute and geometrical parameters. Our solution indicates that V404 Peg is an A‐type overcontact binary with a mass ratio of q = 0.243 and an overcontact degree of f = 32.1 %. Combining our light curves with the radial velocity curves from Maciejewski & Ligeza (2004), we determined the absolute parameters of this system as follows: a = 2.672 R⊙, M1 = 1.175 M⊙, M2 = 0.286 M⊙, R1 = 1.346 R⊙, and R2 = 0.710 R⊙. Finally, we discuss the evolutionary condition of the system (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

3.
New BV light curves and times of minimum light for the short period W UMa system LO And were analyzed to derive the preliminary physical parameters of the system. The light curves were obtained at Ankara University Observatory during 5 nights in 2003. A new ephemeris is determined for the times of primary minimum. The analysis of the light curves is made using the Wilson‐Devinney 2003 code. The present solution reveals that LO And has a photometric mass ratio q = 0.371 and is an A‐type contact binary. The period of the system is still increasing, which can be attributed to light‐time effect and mass transfer between the components. With the assumption of coplanar orbit of the third body the revealed mass is M3 = 0.21M⊙. If the period change dP/dt = 0.0212 sec/yr is caused only by the mass transfer between components (from the lighter component to the heavier) the calculated mass transfer rate is dm/dt = 1.682×10−7M⊙/yr. The absolute radii and masses estimated for the components, based on our photometric solution and the absolute parameters of the systems which have nearly same period are R1 = 1.30R⊙, R2 = 0.85R⊙, M1 = 1.31M⊙, M2 = 0.49M⊙ respectively for the primary and secondary components. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

4.
We present the first long‐term Johnson UBVR observations and comprehensive photometric analysis of the W UMa‐type eclipsing binary V2612 Oph. Observations in the time interval between 2003 and 2009 enabled us to reveal the seasonal and long‐term variations of the light curve. Hence, we found that the mean brightness level of the light curve shows a variation with a period of 6.7 years. Maximum and minimum brightness levels of the light curve exhibit a variation from year to year which we attribute to a solar‐like activity. The O – C variation of eclipse timings of the system shows a decreasing parabolic trend and reveals a period decrease at a rate of P = 6.27×10‐7 day yr‐1 with an additional low‐amplitude sinusoidal variation that has a similar period as the long‐term brightness variations. Our light curve analysis shows that the system is a W‐subtype W UMa eclipsing binary. We calculated masses and radii of the primary and secondary components as M1 = 1.28 M⊙, M2 = 0.37 M⊙ and R1 = 1.31 R⊙, R2 = 0.75 R⊙, respectively. The derived absolute photometric parameters allow us to calculate a distance of 140 pc, which confirms that the system is a foreground star in the sky field of the Galactic open cluster NGC 6633. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

5.
Photometric and spectroscopic characteristics of the WN5+O6 binary system, V444 Cyg, were studied. The Wilson‐Devinney (WD) analysis, using new BV observations carried out at the Ankara University Observatory, revealed the masses, radii, and temperatures of the components of the system as MWR = 10.64 M⊙, MO = 24.68 M⊙, RWR = 7.19 R⊙, RO = 6.85 R⊙, TWR = 31 000 K, and TO = 40000 K, respectively. It was found that both components had a full spherical geometry, whereas the circumstellar envelope of the WR component had an asymmetric structure. The O – C analysis of the system revealed a period lengthening of 0.139 ± 0.018 syr–1, implying a mass loss rate of (6.76 ± 0.39) ×10–6 M⊙ yr–1 for the WR component. Moreover, 106 IUE‐NEWSIPS spectra were obtained from NASA's IUE archive for line identification and determination of line profile variability with phase, wind velocities and variability in continuum fluxes. The integrated continuum flux level (between 1200–2000 Å) showed a mild and regular increase from orbital phase 0.00 up to 0.50 and then a decrease in the same way back to phase 0.00. This is evaluated as the O component making a constant and regular contribution to the system's UV light as the dominant source. The C IV line, originating in the circumstellar envelope, had the highest velocity while N IV line, originating in deeper layers of the envelope, had the lowest velocity. The average radial velocity calculated by using the C IV line (wind velocity) was found as 2326 km s–1 (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

6.
This paper presents the first analysis of spectroscopic and photometric observations of the neglected southern eclipsing binary star, QY Tel. Spectroscopic observations were carried out at the South African Astronomical Observatory in 2013. New radial velocity curves from this study and V light curves from the All Sky Automated Survey were solved simultaneously using modern light and radial velocity curve synthesis methods. The final model describes QY Tel as a detached binary star where both component stars fill at least half of their Roche limiting lobes. The masses and radii were found to be 1.32 (± 0.06) M⊙, 1.74 (± 0.15) R⊙ and 1.44 (± 0.09) M⊙, 2.70 (± 0.16) R⊙ for the primary and secondary components of the system, respectively. The distance to QY Tel was calculated as 365 (± 40) pc, taking into account interstellar extinction. The evolution case of QY Tel is also examined. Both components of the system are evolved main-sequence stars with an age of approximately 3.2  Gy, when compared to Geneva theoretical evolution models.  相似文献   

7.
D. Sürgit  A. Erdem 《New Astronomy》2012,17(3):336-340
This paper presents the first analysis of spectroscopic and photometric observations of the eclipsing binary star WZ Hor. Observations of the system were made at the Mt. John University Observatory in 2007. Since the light contribution of the secondary component was merely 2-3% of the total light of the system in the optical wavelengths, the radial velocity of the primary component could only be determined using the cross-correlation method. A single-lined spectroscopic orbital solution of WZ Hor was obtained, and the BVRI light curves of the system and radial velocity curve of the primary component were analysed simultaneously using the Wilson-Devinney method. The results describe WZ Hor as a reverse Algol-like binary star with a detached configuration. The following absolute parameters of the components were also derived: M1 = 1.51 ± 0.03 M⊙, M2 = 0.66 ± 0.01 M⊙, R1 = 1.62 ± 0.02 R⊙, R2 = 0.66 ± 0.01 R⊙, L1 = 4.93 ± 0.64 L⊙ and L2 = 0.09 ± 0.02 L⊙. The distance to WZ Hor was calculated as 95 ± 8 pc using distance modulus with correction for interstellar extinction, in agreement with the HIPPARCOS value.  相似文献   

8.
From accurate radial‐velocity measurements covering 11 circuits of the orbit of the composite‐spectrum binary 45 Cnc, together with high‐resolution spectroscopy spanning nearly 3 circuits, we have (i) isolated cleanly the spectrum of the early‐type secondary, (ii) classified the component spectra as G8 III and A3 III, (iii) derived the first double‐lined orbit for the system and a mass ratio (M1/M2) of 1.035 ± 0.01, and (iv) extracted physical parameters for the component stars, deriving the masses and (log) luminosities of the G star and A star as 3.11 and 3.00 M⊙, and 2.34 and 2.28 L⊙, respectively, with corresponding uncertainties of ±0.10 M⊙ and ±0.09 L⊙. Since the mass ratio is close to unity, we argue that the more evolved component is unlikely to have been a red giant long enough to have made multiple ascents of the RGB, an argument that is supported somewhat by the rather high eccentricity of the orbit (e = 0.46) and the evolutionary time‐scales of the two components, but chiefly by the presence of significant Li I in the spectrum of the cool giant. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

9.
We present an analysis of BV R light curves of an eclipsing binary CK Bootis, a system with a very small mass ratio. The light curves appear to exhibit a typical O'Connell effect. The light curves are analyzed by means of the latest version of the WD program. The asymmetry of the light curves is explained by a cool star spot model. The simultaneous BV R synthetic light curve analysis gives a tiny mass ratio of 0.12, an extremely large fill‐out factor of 0.65, and a very small difference between the component temperatures of 90 K. The absolute parameters of the system were also derived by combining the photometric solutions with the radial velocity data. The mass of the secondary is very low (0.15 M⊙) and it continues losing mass. Thirty seven new times of minimum are reported. It is found that the orbital period of the system has a quasi periodic variation, superimposed on a period increase. The long‐term period increase rate is deduced to be dP/dt = 3.54x10–7 d yr–1, which can be interpreted as being due to mass transfer from the less massive star to the more massive component. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

10.
In this study we determined precise orbital and physical parameters of the very short‐period low‐mass contact binary system CC Com. The parameters are obtained by analysis of new CCD data combined with archival spectroscopic data. The physical parameters of the cool and hot components are derived as Mc = 0.717(14) M⊙, Mh = 0.378(8) M⊙, Rc = 0.708(12) R⊙, Rh = 0.530(10) R⊙, Lc = 0.138(12) L⊙, and Lh = 0.085(7) L⊙, respectively, and the distance of the system is estimated as 64(4) pc. The times of minima obtained in this study and with those published before enable us to calculate the mass transfer rate between the components which is 1.6 × 10–8 M⊙ yr–1. Finally, we discuss the possible evolutionary scenario of CC Com (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

11.
The Hipparcos Space Astrometry Mission photometric observations of V398 Lac, led to the discovery of its variability, allowing to classify it as an eclipsing binary with an orbital period of about 5.4 days. This prompted us to acquire highresolution échelle spectra with the aim of performing accurate radial velocity measurements and to determine the main physical parameters of the system's components. We present, for the first time, a double‐lined radial velocity curve and determine the orbital and physical parameters of the two components, that can be classified both as late B‐type stars. In particular, we obtained an orbital inclination i ∼ 85°. With this value of the inclination, we deduced masses M1 = 3.83±0.35 M⊙ andM2 = 3.29±0.32 M⊙, and radii R1 = 4.89±0.18 R⊙ and R2 = 2.45±0.11 R⊙ for the more massive and less massive components, respectively. Both components are well inside their own Roche lobes. The mass ratio is M2/M1 ∼ 0.86. We derived also the projected rotational velocities as v1 sin i = 79±2 km s–1 and v2 sin i = 19±2 km s–1. Our measurements indicate that the rotation of the primary star is essentially pseudo‐synchronized with the orbital velocity at the periastron, while the secondary appears to rotate very slowly and has not yet attained synchronization. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

12.
We present the results of our spectroscopic observations of the eclipsing binary SZ Cam performed with the 1-m (Zeiss-1000) and 6-m (BTA) telescopes at the Special Astrophysical Observatory of the Russian Academy of Sciences in 2000 and 2003. Based on our results and published data, we have calculated new values for the component mass ratio, q = 0.72 ± 0.02, the radial velocity of SZ Cam relative to the Solar system barycenter, V 0 =?10.6 ± 2.0 km s?1, and the semi-amplitudes of the radial velocity curves for both components, K 1 = 192.0 ± 2.6 and K 2 = 266.4 ± 2.5 km s?1. The orbital semimajor axes and masses of the components have been determined: α1 = 10.4R ⊙, α2 = 14.5R ⊙, M 1 = 16.7M ⊙, M 2 = 12.0M ⊙. New light elements and parameters of the radial velocity curve for the third body have been obtained. The mass of the secondary component of the third body M 2 3b is discussed. Its lower limit is estimated to be M 2 3b = 1.4M ⊙.  相似文献   

13.
Detached eclipsing binaries constitute potential accurate distance tracers. They are also useful as the test bench of stellar evolution. In BD–00° 3357 eclipses are partial and its orbital period is 1.d4. Our combined spectroscopic and photometric solution yields secure parameters of this system. The model of the star was obtained using the Wilson‐Devinney method. As result we obtained a semi major axis of 7.65 R⊙ and a mass ratio of 0.78. The derived masses and radii are M 1 = 1.73 M⊙,M 2 = 1.34 M⊙R 1 = 1.78 R⊙, R 2 = 1.32 R⊙, respectively. These values correspond to the slightly evolved F0 and F6.5 components, both slightly less than 1Gyr old. The distance of the star was estimated to be 310 ± 60 pc, and the corresponding photometric parallax is 3.24 ± 0.74 mas. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

14.
We present a new orbit for the visual binary ADS 8630 = γ Vir. Although it is one of the first visual double stars discovered, its orbital elements were still poorly known. Indeed the very high eccentricity of the orbit and the difficulty of observing the pair at periastron passage in 1836 has meant that it is only now that sufficient measures of the recent close approach in 2005 have allowed an orbital analysis which predicts the angular motion to an acceptable degree of accuracy. We present a series of 35 speckle measurements of ADS 8630 obtained with PISCO in Merate between 2004 and 2006. Those measures have been crucial for determining the new orbital elements since they cover an arc of 130 degrees in the apparent orbit and include the periastron passage of 2005. The masses of the individual F0V components of the binary are found to be 1.40 M⊙ with an accuracy of about 3%. We also investigate in detail the possibility of the presence of a third body in the system, that was proposed by other authors. The high‐angular resolution infra‐red image of γ Vir that we obtained in June 2006 with the LuckyCam instrument on the ESO NTT shows the absence of any companion as faint as a M0V star at a distance larger than 0.4″. Combined with the analysis of the residuals of our orbit, the values found for the masses of the individual components and the radial velocity measurements, this observation rules out the presence in the system of a third companion with a mass larger than 0.3 M⊙. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

15.
We present the results of our investigation on the geometrical and physical parameters of W UMa-type binary TYC1174-344-1 from analyzed CCD (BVRI) light curves and radial velocity data. The photometric data were obtained in 2009 at Ankara University Observatory (AUO) and the spectroscopic observations were made in 2008 at Astrophysical Observatory of Asiago (Italy). Light and radial velocity observations were analyzed simultaneously by using the well-known Wilson–Devinney (2007 revision) code to obtain absolute and geometrical parameters. According to our solutions, the system is found to be a low mass-ratio A-type W UMa system. Combining our photometric solution with the spectroscopic data, we derived mass and radii of the eclipsing system as M1 = 1.381 M⊙, M2 = 0.258 M⊙, R1 = 1.449 R⊙ and R2 = 0.714 R⊙. We finally discussed the evolutionary condition of the system.  相似文献   

16.
We present photometric observations of two post-common-envelope stars, NY Vir (=PG 1336-018) and HS 0705 + 6700. The V band CCD observation of NY Vir was performed by a 40 cm telescope at Ege University Observatory and the R band observations of HS 0705 + 6700 were performed by 100 cm telescope at TÜB?TAK National Observatory. The new light curves were analyzed by the WD code and the physical parameters of stars were determined. We obtained new mid-eclipse timings for HS 0705 + 6700 and combined them with those previously published data. The analysis of the O-C residuals yields a period of about 8.06 ± 0.28 yr and an amplitude of 98.5 s for the system HS 0705 + 6700, which is attributed to the third star physically bounded to the evolved eclipsing pair. A mass function of 1.2 × 10−4 M⊙ for the third star is obtained. The existence of a third star is also confirmed by the light curve analysis, indicating light contribution of about 0.043 at phase 0.25 in R-bandpass of the eclipsing pair. Using mass-luminosity relationship of the low mass stars we estimate a mass of 0.12 M⊙ with an orbital inclination of about 20°. The O-C residuals obtained for the system NY Vir were represented by a downward parabola which indicates orbital period decrease in the system. Using the coefficient of quadratic term we calculate a rate of orbital period decrease of about dP/dt = −4.09 × 10−8days yr−1. The period decrease we have measured in NY Vir may be explained by angular momentum loss from the binary system.  相似文献   

17.
We obtained multi-colour light curves of the overcontact binary system HH Boo and analysed the orbital period variation of the system. Our analysis tentatively indicates either mass transfer from the secondary to the primary or mass loss from the system at a rate of -5.04 × 10−7 M⊙ per year. Through a combined analysis of the published radial velocity curve and light curves, we determined an inclination (i) of 69°.71 ± 0°.16 and a semi-major axis (a) of 2.246 ± 0.064 R⊙ for HH Boo. The masses of the primary and secondary components were found to be 0.92 ± 0.08 M⊙ and 0.58 ± 0.06 M⊙, respectively. The radius determined for the primary was 0.98 ± 0.03 R⊙, while that determined for the secondary was 0.80 ± 0.02 R⊙. We demonstrated that HH Boo is most likely a member of the A-type subclass of W UMa binaries.  相似文献   

18.
  相似文献   

19.
Complete UBV light curves of the W Ursae Majoris binary V839 Ophobtained in the year 2000 are presented. The available spectroscopic data of V839 Oph is new and we used the first radial velocity data of this system obtained by Rucinski and Lu (1999)for analysis. The radial velocity and light curves analysis was made with the latest version of Wilson programme (1998) and the geometric and physical elements of the system are derived. By searching the simultaneous solutions of the system we have determined the masses and radii of the components: 1.61M ⊙and 1.49402R ⊙ for the primary component; 0.50M ⊙and 0.90147R ⊙ for the secondary component. We estimate deffective temperatures of 6650±18 (K) for the primary and6554±15 (K) for the secondary component. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

20.
New radial velocity and photometric data for BO Ari have been obtained, and Roche-based simultaneous analysis of RV and light curve data for the system has been accomplished using the 2003 version of the Wilson-Devinney code. Values for the masses and radii have been obtained: M1 = 1.34 (2) Mʘ, M2 = 0.26 (1) Mʘ, and R1 = 1.25 (2) Rʘ, R2 = 0.61 (2) Rʘ. For the luminosities the most likely values are L1 = 1.67 (15) Lʘ and L2 = 0.42 (4) Lʘ, each the mean of two values. There is poor agreement with earlier values by Gurol et al. (2015). During the light curve modelling, solutions were found with a small third light contribution, but the existence of the latter cannot be established unambiguously owing to the very close residuals of the different solutions. A third component was not found in the RV data within detection limits.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号