双星与变星研究组知识库

Two twin binaries, KIC 4826439 and KIC 6045264, with very similar component stars were found photometrically based on Kepler eclipsing binary light curves. The absolute parameters of the massive components are 1.156(0.03) M-circle dot, 1.881(0.02) R-circle dot, 6065 K for KIC 4826439, and 0.874(0.3) M-circle dot, 1.206(0.02) R-circle dot, 6169(30) K for KIC 6045264. The differences between the components are less than two percent for all the parameters. A very low proportion of twin binaries (2/1592 approximate to 0.13%) was found, which does not support the previous findings of excesses of twins on binary mass ratio distribution, but supports a deficiently low proportion of twins. A new method is used to work out the absolute parameters of the two twins without the radial velocities. This method requires the solution of the light curves, the spectra, and the evolutionary isochrones covering the complete stellar parameter space, simultaneously. We also studied their evolution tracks: KIC 4826439 will experience an unstable mass transfer stage followed by an unclear ending, and KIC 6045264 will become a single star via an over-contact phase. It seems highly unlikely that the two twin binaries will produce twin degenerate binaries, although they have quite similar components.