KIC 6464285: A Solar-type Eclipsing Binary in a Hierarchical Triple System with Quasiperiodic Out-of-eclipse Modulations
Annotatsiya
Abstract We present the first detailed analysis of the solar-type triple system KIC 6464285. Combining long-term, high-precision photometry from Kepler, the Transiting Exoplanet Survey Satellite, and the Zwicky Transient Facility with low-resolution spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope and near-infrared high-resolution spectra from the Apache Point Observatory Galactic Evolution Experiment of the Sloan Digital Sky Survey, we performed a joint analysis of the light curves (LCs), eclipse timing variations (ETVs), and radial velocities. Spectroscopic analysis reveals the system to be triple-lined, with the inner binary’s primary being a G-type main-sequence star and a mass ratio of 0.627(7). LC modeling indicates that the inner binary is detached, with filling factors of approximately 26% and 11% for the primary and secondary, respectively, and a tertiary light contribution of about 27%. ETV analysis shows a significant light-travel-time effect (LTTE), consistent with the presence of the tertiary companion, whose minimum mass is estimated as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>,</mml:mo> <mml:mi mathvariant="normal">min</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>0.74</mml:mn> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo stretchy="false">)</mml:mo> <mml:mspace width="0.25em"/> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> . The LC exhibits a pronounced O’Connell effect and quasiperiodic variations, indicative of starspot activity modulating the photometry on a ∼131 day timescale. Kepler observations further reveal 30 superflares, each with total energies exceeding 10 34 erg. This study presents detailed observational constraints on the orbital configuration, stellar properties, and magnetic activity of KIC 6464285, providing a benchmark for studies of hierarchical triple systems.