New photometric solutions of contact binaries HX UMa and FP Boo

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By using different databases (TESS, SuperWASP, KWS and ASAS-SN), light curve analyzes of HX UMa and FP Boo systems were performed, and the changes in the orbital period of the systems were also examined. The light curve analyzes of the systems were conducted simultaneously with the radial velocities using the Wilson and Devinney (WD) code. As a result of the analyzes, the masses and radii of the components were determined as M 1 = 1 . 29 ± 0 . 02 M ⊙ , M 2 = 0 . 38 ± 0 . 02 M ⊙ , R 1 = 1 . 21 ± 0 . 02 R ⊙ , R 2 = 0 . 78 ± 0 . 02 R ⊙ for HX UMa and M 1 = 1 . 68 ± 0 . 05 M ⊙ , M 2 = 0 . 16 ± 0 . 01 M ⊙ , R 1 = 2 . 28 ± 0 . 02 R ⊙ , R 2 = 0 . 82 ± 0 . 02 R ⊙ for FP Boo, respectively. The distances of HX UMa and FP Boo were calculated as 123 ± 11 pc and 350 ± 23 pc, respectively, and were almost the same as Gaia DR3 values. When the orbital period changes were examined, it was determined that the orbital period of the HX UMa system increased, while the FP Boo decreased. The orbital period increase rate of HX UMa was calculated as d P / d t = 9 × 1 0 − 8 d yr −1 and the period decrease rate of FP Boo was calculated as d P / d t = 1 . 7 × 1 0 − 6 d yr −1 . Mass transfer between components has been suggested as the reason for the period changes. Along with the orbital period changes, a cyclical change was observed in both systems. Magnetic activity or a possible third component can cause cyclical variation. The periods of these cyclical changes are determined as 24 ± 4 yr and 20 ± 1 yr, respectively. • In this study, light curves taken from different databases are analyzed simultaneously with radial velocity and it is very important because basic astrophysical parameters are determined. • Minima times were calculated for the HX UMa from both TESS and SuperWASP data. • A total of 24 minima times were calculated from 4 different observations from TESS data for FP Boo. • It is very important to determine the basic parameters such as mass radius and temperature with more sensitive data and the distances calculated from photometry are almost the same as the Gaia DR3 distances. • Detailed orbital period analysis studies will also make significant contributions to the literature. • The orbital period analysis of HX UMa was performed for the first time in this study. • The orbital period analysis for FP Boo was carried out in detail in this study and quite different results were obtained from the last study (The reason for this is that almost twice as much data analysis was made as in the last study).