In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photom...In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photometric solutions suggest that NSVS 9023048 is a deep contact binary(q=10.14,f=69.2%),however,NSVS 2461789is a shallow one(f=24.4%,q=3.08).The asymmetric light curves of NSVS 2461789 and NSVS 9023048 can be explained by the star-spot activity.At the same time,using the available eclipse times,we first studied the orbital period changes of these two targets.It is discovered that the period of NSVS 9023048 is decreasing at a rate of dP/dt=-1.17×10^(-6)day yr^(-1),which can be explained by mass transfer from the more massive star to the less massive one or angular momentum loss.In addition,the O-C diagrams of NSVS 9023048 and NSVS 2461789show possible cyclic oscillations with a period of 7.29 yr and 9.91 yr,respectively.The cyclic oscillations may be caused by the light-travel time effect due to the presence of a third component.The mass of the tertiary companion is determined to be M_(3)sin(i_(3))=9.05 Mefor NSVS 9023048 and M_(3)sin(i_(3))=0.11 Mefor NSVS 2461789.Based on our calculations,the third body of NSVS 9023048 may be a black hole candidate.Our study also reveals that NSVS 9023048 is stable now.展开更多
In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times ...In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times of minimum light compiled from the literature.As a result,the apsidal motion periods were determined to be 353±50 yr,43.3±5.1 yr and 83.4±8.5 yr,respectively.Furthermore,the TESS light curves of the three systems were analyzed to derive their photometric and absolute parameters.The component masses were determined as follows:for V398 Lac,M_(1)=3.83±0.35 M_(⊙)and M2=3.27±0.35 M_(⊙);for V2544 Cyg,M_(1)=1.75±0.38 M_(⊙)and M2=1.40±0.38 M_(⊙);for V785 Cas,M_(1)=5.64±0.41 M_(⊙)and M2=5.18±0.41 M_(⊙).The parameters related to apsidal motion,as well as the observational and theoretical internal structure constants(K_(2,obs) and K_(2,teo))were calculated for studied binaries.The relativistic contribution to the observed apsidal motion rate was found to be relatively small,constituting less than approximately 5%of the total rate in each system.The theoretical internal structure constants were derived from the evolutionary models,assuming a standard chemical composition of(X,Z)=(0.70,0.01).展开更多
We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Trans...We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11988101,U1931101,42364001 and 11933008)the Foundation of Education Bureau of Guizhou Province,China(No.KY(2020)003)+1 种基金the Guizhou Provincial Science and Technology Foundation(No.ZK[2022]322)the Guizhou Normal University 2019Special project of training new academics。
文摘In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photometric solutions suggest that NSVS 9023048 is a deep contact binary(q=10.14,f=69.2%),however,NSVS 2461789is a shallow one(f=24.4%,q=3.08).The asymmetric light curves of NSVS 2461789 and NSVS 9023048 can be explained by the star-spot activity.At the same time,using the available eclipse times,we first studied the orbital period changes of these two targets.It is discovered that the period of NSVS 9023048 is decreasing at a rate of dP/dt=-1.17×10^(-6)day yr^(-1),which can be explained by mass transfer from the more massive star to the less massive one or angular momentum loss.In addition,the O-C diagrams of NSVS 9023048 and NSVS 2461789show possible cyclic oscillations with a period of 7.29 yr and 9.91 yr,respectively.The cyclic oscillations may be caused by the light-travel time effect due to the presence of a third component.The mass of the tertiary companion is determined to be M_(3)sin(i_(3))=9.05 Mefor NSVS 9023048 and M_(3)sin(i_(3))=0.11 Mefor NSVS 2461789.Based on our calculations,the third body of NSVS 9023048 may be a black hole candidate.Our study also reveals that NSVS 9023048 is stable now.
基金Funding for TESS is provided by the NASA Science Mission Directorate。
文摘In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times of minimum light compiled from the literature.As a result,the apsidal motion periods were determined to be 353±50 yr,43.3±5.1 yr and 83.4±8.5 yr,respectively.Furthermore,the TESS light curves of the three systems were analyzed to derive their photometric and absolute parameters.The component masses were determined as follows:for V398 Lac,M_(1)=3.83±0.35 M_(⊙)and M2=3.27±0.35 M_(⊙);for V2544 Cyg,M_(1)=1.75±0.38 M_(⊙)and M2=1.40±0.38 M_(⊙);for V785 Cas,M_(1)=5.64±0.41 M_(⊙)and M2=5.18±0.41 M_(⊙).The parameters related to apsidal motion,as well as the observational and theoretical internal structure constants(K_(2,obs) and K_(2,teo))were calculated for studied binaries.The relativistic contribution to the observed apsidal motion rate was found to be relatively small,constituting less than approximately 5%of the total rate in each system.The theoretical internal structure constants were derived from the evolutionary models,assuming a standard chemical composition of(X,Z)=(0.70,0.01).
基金support from the National Research Foundation(NRF)of South Africasupported by the Ministry of Science and Higher Education of Russia,topic No.FEUZ-2023-0019。
文摘We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.
