Study On The Physical Properties Of Eclipse Binaries Based On LAMOST Mid-and Low-resolution Spectral Survey Data

There are a large number of eclipse binaries in the Milky Way.For many eclipse binaries,we do not know their physical parameters and spectral activity properties.In order to better understand the spectral properties of eclipse binaries and their chromospheric activity,the large sample star spectral library of the LAMOST telescope provides important information for us to study the spectral properties of eclipse binaries.It can not only reveal the properties and laws of the magnetic activity of eclipsing binaries,but also provide information and limitations for the improvement of theoretical models,and further develop the stellar dynamo theory.The main research results of this work are as follows:(1)we cross-match the LAMOST low-and medium-resolution spectrum data with variable stars table,32719 eclipse binaries with spectral data were obtained.By calculating the chromospheric activity index(H? line)to determine the chromospheric activity level and found that there are 10,372 eclipsing binaries with chromospheric activity.We counted the activity ratio of M-type eclipsing binaries,and found that the H? activity ratio of M0 to M4 is increasing,and its activity ratio is higher than that of single star.We also found that 7,230 stars exhibit H? variability.Through statistical research,we found that there are correlation between the equivalent width of the activity index H? line of these eclipse binaries and the period and radius: as the rotation period or the radius of the star gradually increases,the equivalent width of the H? line gradually decreases,and then reaches a certain threshold and begins to saturate.(2)Then,we used optical telescopes at home and abroad to conduct follow-up photometric observation studies on 7 low-mass eclipse binaries with chromospheric activity,of which 4 are M-type binaries(HAT 225-03429,CRTS J085623.0 + 282620,CRTS J110302.4 + 201611,2MASS J16344899 + 3716423),and 3 are W Uma type eclipses(V574 Lyr,V1033 Her and V1062 Her).We use the Wilson-Devinney program to solve the orbital parameters and starspot parameters of these seven eclipse binaries.We found starspots variability of about one month for V574 Lyr,and on long(years)time-scales for V1033 Her and V1062 Her.There are also obvious variations in the differences of light-curve maxima between 0.25 and 0.75 phases.Simultaneously,we analyzed the period variation of 3 systems(V574 Lyr,V1033 Her,and V1062 Her),found that V574 Lyr and V1062 Her show a cyclic variation,caused by the light-time effect via the third body or magnetic activity cycle,while the period of V1033 Her shows a continuous increase trend,the reason for this continuous increase is the transfer of mass from a smaller mass primary star to a larger mass secondary star.Finally,in the future,we will combine the data released by other sky survey projects such as Kepler,TESS,Gaia,etc.and use more characteristic spectral lines and parameters to further study the magnetic activity properties of eclipsing binaries.The eclipse binaries with relatively strong magnetic activities were used for long-term follow-up observations with the one-meter optical telescope at the Observatory at home and abroad to reveal the evolutionary laws of magnetic activities.