共查询到20条相似文献，搜索用时 984 毫秒
1.
New BVR light curves and a photometric analysis of the eclipsing binary star V1430 Aql are presented. The light curves were obtained at the Çanakkale Onsekiz Mart University Observatory in 2004. The light curves are generally those of detached eclipsing binaries, but there are large asymmetries between maxima. New BVR light curves were analysed with an ILOT procedure. Light curve asymmetries of the system were explained in terms of large dark starspots on the primary component. The primary star shows a long‐lived and quasi‐poloidal spot distribution with active longitudes in opposite hemispheres. Absolute parameters of the system were derived.We also discuss the evolution of the system: the components are likely to be pre‐main sequence stars, but a post‐main sequence stage cannot be ruled out. More observations are needed to decide this point. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
2.
We present photometric analysis of 8 short-period eclipsing binaries discovered and observed at Astronomical Observatory at Kolonica Saddle between 2007 and 2010 with different instruments. We determined their orbital periods and performed photometric analysis of their light curves. We found that 3 systems are detached binaries, 4 systems are over-contact binaries of W UMa type and one system is semi-detached with the secondary component filling its Roche lobe. Light curves of 2 systems exhibit asymmetries, explained by spot(s) on the surface of the components. 相似文献
3.
We present observations and light curve analysis of the eclipsing binary R CMa in the narrow band filters v and b. Observations were made during 1993 at Biruni Observatory and the light curves have been analyzed using the Wilson-Devinney
light curve interpretation program. Assuming a semi-detached configuration for R CMa, the parameters i, Ω1, L
1, T
2 and A
2 were adjusted for the best fit between the synthesized light curves and observations. Both light curves were fitted well
with a lower value of bolometric albedo than what would be expected for a normal cool star with a convective envelope. The
masses of the primary and secondary components and the absolute dimensions of the stars have been calculated using the derived
relative dimensions from Wilson-Devinney codes and the spectroscopic observations. 相似文献
4.
Two CCD epochs of light minimum and a complete R light curve of SS Ari are presented. The light curve obtained in 2007 was
analyzed with the 2003 version of the W-D code. It is shown that SS Ari is a shallow contact binary system with a mass ratio
q=3.25 and a degree of contact factor f=9.4%(±0.8%). A period investigation based on all available data shows that there may exist two distinct solutions about the
assumed third body. One, assuming eccentric orbit of the third body and constant orbital period of the eclipsing pair, results
in a massive third body with M
3=1.73M
⊙ and P
3=87.0 yr. On the contrary, assuming continuous period changes of the eclipsing pair the orbital period of tertiary is 37.75
yr and its mass is about 0.278M
⊙. Both of the cases suggest the presence of an unseen third component in the system. 相似文献
5.
Yuangui Yang 《Astrophysics and Space Science》2008,314(1-3):151-162
This paper presents charge-couple device (CCD) photometric observations for the eclipsing binary AW UMa. The V-band light
curve in 2007 was analyzed using the 2003 version of the Wilson–Devinney code. It is confirmed that AW UMa is a total eclipsing
binary with a higher degree of contact f=80.2% and a lower mass ratio of q=0.076. From the (O−C) curve, the orbital period shows a continuous period decrease at a rate of dP/dt=−2.05×10−7 d yr−1. The long-term period decrease suggested that AW UMa is undergoing the mass transfer from the primary component to the secondary
one, accompanied by angular momentum loss due to mass outflow L
2. Weak evidence indicates that there exists a cyclic variation with a period of 17.6 yr and a small amplitude of A=0.
d
0019, which may be attributed to the light-time effect via the third body. If the existence of an additional body is true,
it may remove a great amount of angular momentum from the central system. For this kind of contact binary, as the orbital
period decreases, the shrinking of the inner and outer critical Roche lobes will cause the contact degree f to increase. Finally, this kind of binary will merge into a single rapid-rotation star. 相似文献
6.
7.
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.
《New Astronomy》2015
Analyzing available photometry from the Super WASP and other databases, we performed the very first light curve analysis of eight eclipsing binary systems V537 And, GS Boo, AM CrB, V1298 Her, EL Lyn, FW Per, RU Tri, and WW Tri. All of these systems were found to be detached ones of Algol-type, having the orbital periods of the order of days. 722 new times of minima for these binaries were derived and presented, trying to identify the period variations caused by the third bodies in these systems. 相似文献
9.
The unique (1954–1956) photoelectric B and V light curves of the EB‐type eclipsing variable FU Ara are here analyzed. The Wilson‐Devinney Differential Correction program was used and the analysis of the results shows that the best fit was obtained at photometric mass ratio q = 0.399 and inclination i = 83°, the primary minimum shows a transit. The star is a semi‐detached system with the secondary that accurately fills its limiting lobe. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
11.
A new orbital period analysis for U Geminorum is made by means of the standard O–C technique based on 187 times of light minima
including the three newest CCD data from our observation. Although there are large scatter near 70,000 cycles in its O–C diagram,
there is strong evidence (>99.9% confidence level) to show the secular increase of orbital period with a rate
s−1. Using the physical parameters recently derived by Echevarría et al. (Astron. J. 134:262, 2007), the range of mass transfer rate for U Geminorum is estimated as from −3.5(5)×10−9 M
⊙ yr−1 to −1.30(6)×10−8 M
⊙ yr−1. Moreover, the data before 60,000 cycles shows the obvious quasi-period variations. The least square estimation of a ∼17.4 yr
quasi-periodic variation superimposed on secular orbital period increase is derived. Considering the possibility that solar-type
magnetic activity cycles in the secondary star of U Geminorum may produce the quasi-period variations of the orbital period,
Applegate’s mechanism is discussed and the results indicate such mechanism has difficulty explaining the quasi-period variation
for U Geminorum. Hence, we attempted to apply the light-travel time effect to interpret the quasi-period variation and found
the perturbation of ∼17.4 yr quasi-period may result from a brown dwarf. If the orbital inclination is assumed as i∼15°, corresponding to the upper limit of mass of a brown dwarf, then its orbital radii is ∼7.7 AU. 相似文献
13.
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
14.
15.
St. Raetz M. Va&#x;ko M. Mugrauer T.O.B. Schmidt T. Roell T. Eisenbeiss M. M. Hohle A. Koeltzsch Ch. Ginski C. Marka M. Moualla N. Tetzlaff Ch. Broeg R. Neuhuser 《Astronomische Nachrichten》2009,330(5):504-510
We report on observations of the eclipsing binary 2MASS 19090585+4911585 with the 25 cm auxiliary telescope of the University Observatory Jena. We show that a nearby brighter star (2MASS 19090783+4912085) was previously misclassified as the eclipsing binary and find 2MASS 19090585+4911585 to be the true source of variation. We present photometric analysis of VRI light curves. The system is an overcontact binary of W UMa type with an orbital period of (0.288374 ± 0.000010) d (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
Diana Kjurkchieva Dragomir Marchev Tatiana Khruzina Gojko Djurašević 《Astrophysics and Space Science》2006,306(4):217-229
UBVRI photometry and spectroscopic observations around the Hα line of the cataclysmic star UX UMa are presented. The analysis of the 9-year photometry shows that the out-of-eclipse brightness
of the system and the depth of the eclipse changes in different time scales while the width of the eclipse remains constant.
The observed features of the light curves as well as the features of the two-peaked Hα profiles were attributed to an inhomogeneity of the accretion disk. “Spiral arm” model for a fitting of the light curves
of UX UMa is proposed. It reproduces well the observational data. The obtained azimuthal extent of the spiral arms is of ∼90°
and their light contribution is about 17–30of the total V flux of the disk. The obtained two dense structures at the outer
disk covering partially the inner hot disk and the white dwarf at orbital phases ∼0.7 and ∼0.2 is in agreement with the predictions
of the theoretical computations. 相似文献
17.
18.
Interstellar and atmospheric extinctions redden the observational photometric data and they should be handled rigorously.
This paper simulates the effect of reddening for the modest case of two main sequence T
1 = 6500 K and T
2 = 5500 K components of a detached eclipsing binary system. It is shown that simply subtracting a constant from measured magnitudes
(the approach often used in the field of eclipsing binaries) to account for reddening should be avoided. Simplified treatment
of the reddening introduces systematics that reaches ∼0.01 mag for the simulated case, but can be as high as ∼0.2 mag for,
e.g., B8 V-K4 III systems. With rigorous treatment, it is possible to uniquely determine the colour excess value E(B−V) from multi-colour photometric light curves of eclipsing binaries. 相似文献
19.
《New Astronomy》2015
In this article, a period analysis of the late-type eclipsing binary VV UMa is presented. This work is based on the periodic variation of eclipse timings of the VV UMa binary. We determined the orbital properties and mass of a third orbiting body in the system by analyzing the light-travel time effect. The O−C diagram constructed for all available minima times of VV UMa exhibits a cyclic character superimposed on a linear variation. This variation includes three maxima and two minima within approximately 28,240 orbital periods of the system, which can be explained as the light-travel time effect (LITE) because of an unseen third body in a triple system that causes variations of the eclipse arrival times. New parameter values of the light-time travel effect because of the third body were computed with a period of 23.22 ± 0.17 years in the system. The cyclic-variation analysis produces a value of 0.0139 day as the semi-amplitude of the light-travel time effect and 0.35 as the orbital eccentricity of the third body. The mass of the third body that orbits the eclipsing binary stars is 0.787 ± 0.02 M⊙, and the semi-major axis of its orbit is 10.75 AU. 相似文献
20.
《New Astronomy》2015
An updated period analysis for the overcontact eclipsing binary ER Orionis is presented. Featured is an improved derivation of parameters for the light time effect (LTE) due to the third star (in actuality, a pair of stars) utilising the latest set of eclipse timings. The very good fit between the eclipse timing differences (ETD) plot (otherwise known as an O–C diagram) and the theoretical ETD curve makes possible an improved determination of the rate of mass interchange between the binary pair, dm1/dt = +1.83(6) × 10−7 Mʘ/year. In addition, the mass of the companion system (in actuality, m3 sin i) and the elements of its orbit were computed. A suggestion is made for a method of future determination of the inclination of the orbit of the companion system. 相似文献