共查询到20条相似文献，搜索用时 46 毫秒
1.
PhotoelectricB andV observations of the W UMa-type system OO Aql have been obtained for 11 nights during the period from 22 June–30 July, 1987. A total of 978 observations were obtained in eachB andV filter. All these observations were transformed to theB andV colours of theUBV standard system. Five light curves for primary and secondary eclipses were obtained, its times of minima were determined and a new linear ephemeris was given. The period changes of the system were discussed. 相似文献
2.
U. S. Chaubey 《Astrophysics and Space Science》1982,81(1-2):283-293
The light curves of eclipsing binary DI Pegasi inU, B. andV filters have been presented and discussed. Photometric elements of the system have been determined. Using the colour indices, we estimate absolute dimensions and discuss the evolutionary status of the system. 相似文献
3.
J. B. Srivastava 《Astrophysics and Space Science》1976,40(1):15-34
Photoelectric and absolute elements of the system CD Tau have been determined inU, B andV filters. The system is a detached one. 相似文献
4.
The photoelectric elements of the system VZ Hydrae have been redetermined inU, B andV colours. Our results are at variance from those given earlier by Walker. The colour of the system has also been given. The system is a detached one. 相似文献
5.
The system of ST Aquarii has been observed inB andV filters at KOTTAMIA Observatory in Egypt. Two light curves have been obtained and new times of minima have been calculated.The light curves have been analysed using the theory of Fourier transform of light changes in frequencydomain, and new geometrical and physical elements have been obtained. 相似文献
6.
Limiting photometric solutions for the system CD Eri inB andV filters have been obtained. The secondary minimum was found to be absent. 相似文献
7.
Photoelectric and absolute elements of the system RT Per have been determined inU, B, andV filters. It is suggested that the primary star may be surrounded by a gaseous disk. 相似文献
8.
Z. Tunca 《Astrophysics and Space Science》1984,105(1):23-31
The RS CVn-type eclipsing binary SZ Psc was observed in two coloursB andV, in 1981. The rate of change of the period was calculated using two different least-squares procedures. The amplitudes of the light variations at outside eclipses are 0
.
m
181 and 0
.
m
213 inB andV colours, respectively. The light curves of the system have been solved using a new approximation. The radius of the cooler component is only 82% of its Roche-radius and the system is detached one. 相似文献
9.
M. Kuturaç C. Ibanoğlu Z. Tunca A. Y. Ertan S. Evren O. Tümer 《Astrophysics and Space Science》1981,77(2):325-346
The RS CVn-type eclipsing binary AR Lac has been observed in two colours,B andV, in 1978 and 1979. Several times of minima have been obtained during the observations and the new light elements have been calculated. The orbital period of the system was found to be decreasing with an amount of 14.6 s century–1.The light curves of the system obtained inB andV show a significant wave-like distortion outside eclipses. The amplitudes of the wave-like distortion inB andV are about 0
.
m
09 and 0
.
m
10 in 1978, and, 0
.
m
12 and 0
.
m
13 in 1979, respectively. The minima of the wave-like distortion have shifted with an amount of 0
.
p
40 in one year, thus indicating the migration period of the wave-like distortion is about 2.5 yr.A noticeable variation of light during the totality of primary minimum has also been observed. This variation can be attributed to the distortion wave which has been moving towards decreasing phases. 相似文献
10.
Photoelectric observations of WX Eridani inB andV filters have been discussed. The maximum magnitudes of the system areB=9
m
.70 andV=9
m
.46. TheB-V colours of the components are 0
m
.16 and 0
m
.80 for the primary and the secondary, respectively, while their spectral types are A5+K0. The period has been found to be constant and its revised value is 0d.823 270 76. 相似文献
11.
Photoelectric observations of the eclipsing binary GO Cyg have been carried out inB andV colours at the Ege University Observatory. The corresponding light curves were analyzed by the method of Wilson-Devinney. The system was found to be a reverse Algol semi-detached binary. The absolute elements of the system are also deduced. 相似文献
12.
Vibrational transition probabilities: namely, Franck-Condon factors andr-centroids, have been evaluated using an approximate analytical method for theB-A system of MgO. Morse potential energy curves forB
1+ andA
1 states of MgO have been constructed by use of the latest spectroscopic data. The value ofr-centroids for the band have been found to decrease linearly with the corresponding wavelength. We show results for six new bands in the umbral spectrum of the Sun. 相似文献
13.
U. S. Chaubey 《Astrophysics and Space Science》1992,189(2):263-270
TheU, B, andV photometric observations of the eclipsing binary MM Cas have been presented and discussed. The photometric elements have been derived. By use of the colour indicesU-B andB-V, the spectral types of the systemic components are estimated. An examination of all available times of minimum light of MM Cas does not reveal any change in its orbital period. 相似文献
14.
The W UMa-system U Pegasi was observed photoelectrically in two wavebands (B andV) in 1984. The light curves of this system are analysed using Kopal's frequency-domain technique and the optimisation method. New geometrical and physical elements have been determined and the period-variations discussed. 相似文献
15.
M. Hoffmann 《Astrophysics and Space Science》1982,83(1-2):203-207
Photoelectric light curves of V1022 Oph inB andV are presented. It has been confirmed that it is a W UMa type eclipsing binary with one of the shortest periods known (P<0.d25). Some general properties of the system have been derived.Based on observations made at the European Southern Observatory (La Silla/Chile) 相似文献
16.
C. Sezer 《Astrophysics and Space Science》1993,208(1):15-31
Photoelectric observations of the eclipsing binary V 1073 Cyg have been carried out inB andV colours at the Ege University Observatory. The light curves were analyzed with the Wilson-Devinney approach. A period study reveals that the orbital period of the system is decreasing at the rate of (3.21 ± 0.17) second per century. 相似文献
17.
A. Y. Ertan O. Tumer Z. Tunca C. Ibanoĝlu M. Kurutac S. Evren 《Astrophysics and Space Science》1982,87(1-2):255-268
The eclípsing binary AR Lac has been observed in two colours,B andV, in 1980 and 1981. The new times of minimal obtained during the observatons indicate that the period of the system is still continuing its decrease. The wave-like distortions outside eclipses have two maxima and are very similar in shape in successive two years. 相似文献
18.
This paper presents two new light curves (inB andV) of the eclipsing variable staru Her which have been derived from photoelectric observations made at the National Observatory of Athens. General information of the system is given in the introduction, while Section 2 deals with some observational and reductional details. Section 3 gives the residuals O-C and Section 4 the normal points. 相似文献
19.
S. Evren 《Astrophysics and Space Science》1985,108(1):113-123
The RS CVn-type eclipsing binary star MM Her has been observed in two colours,B andV, in 1979, 1980, and 1983. Several minima times were obtained during the observations and new light elements calculated. The light curves of the system obtained in blue and yellow lights show a significant wave-like distortion which migrates towards the decreasing orbital phases. Its migration period was estimated to be about 3.5 yr. The amplitudes of the wave-like distortion inB andV appear to change each year. The primary minimum of the system is a total eclipse with a duration of 0d.08. 相似文献
20.
TheV andB light curves of three Algol-type eclipsing binaries (UZ Cyg, VW Cyg, AQ Peg), observed by Ammanet al. (1979), have been analysed using the Wilson and Devinney (1971) model. We find that all of them are semi-detached systems, with A-type primary components and K-type evolved secondary which fill the corresponding lobe, although VW Cyg should perhaps be considered as an sd-d system. 相似文献