Searching for Circumbinary planets on selected eclipsing binary systems

Abstract

This research was aimed to searching for circumbinary planets on selected eclipsing binary system such as RR Cae, V619 Peg, V460 Cam, EC10246-2707, J082053.53+000843.4 and BQ Ari. The data obtained observation at the Thai National observatory, the PROMPT - 8 telescope at Cerro Tololo Inter-American Observatory, Chile, Thai Robotic Telescope at SpringBrook observatory, Australia, Regional Observatory for Public, Chachoengsao, Thailand, and Transiting Exoplanet Survey Satellite (TESS). The O − C diagram analyses of RR Cae show that the two period variation that might be exoplanet by the two circumbinary planets in RR Cae. The parameters of two circumbimary planets of P3 = 15.0±0.6 years, P4 = 39±5 years, M3 = 3.0±0.3MJup, M4 = 2.7±0.7MJup, a3 = 5.2 ± 0.1 AU and a4 = 9.7 ± 0.9 AU. The physical parameters from PHOEBE code of RR Cae such as M1 = 0.46 ± 0.12M⊙, M2 = 0.17 ± 0.07M⊙, R1 = 0.03R⊙ , R2 = 0.26R⊙, a = 1.63R⊙ and T2 = 2930K. Moreover, the spot on the secondary star has the variation between 2018 and 2020. The O − C diagram of V619 Peg are shown the period variation due to the third component that might be the M-type of star. The third component has P3 = 10.30 ± 0.14 years, M3 = 0.35 ± 0.02M⊙ and a3 = 6.5 ± 0.1 AU. The physical parameters of V619 Peg were M1 = 2.2 ± 0.1M⊙, M2 = 0.41 ± 0.02M⊙, R1 = 1.70+0.04R⊙, R2 = 0.85 ± 0.02R⊙, T2 = 6402+89 K, i = 82° and f = 0.56. For the spot on primary star were co-latitude = 97°, longitude = 183° , radius = 5° and temperature factor = 0.8. V470 Cam, The O − C diagram was shown the two period variation that can be illustrate the two circumbinary planets. The parameters of the two circumbinary planets were P3 = 8.3±0.2 years, P4 = 13.1±0.2 years, M3 = 0.026±0.001M⊙, M4 = 0.015± 0.001M⊙, a3 = 3.5 ± 0.5 AU, a4 = 4.7 ± 0.5 AU, e3 = 0.067 and e4 = 0.53. EC10246-2707, The O − C diagram of EC10246-2707 has the cyclic period due to the third component. That has the orbital period variation of 11.3 ± 1.8 years, the mass of 0.0012 ± 0.0007M⊙ and the projected semi-major axis of 4.2 ± 0.5 AU. It might be the circumbinary planet in this system. However, the must more data to the monitoring in the future for confirm this result. For J082053.53+000843.4, the O − C diagram has not present the period variation while the orbital period decreased at rate 3.89 ± 3.75 × 10−13 days per cycle. For BQ Ari, the O − C diagram was shown the cyclic variation due to the third component that might be the M-type of star. The orbital period variation was 7.54 ± 0.04 years, the third mass was 0.0948M⊙ and the projected semi-major axis was 3.96 AU.