Testing the mirror world hypothesis for the close-in extrasolar planets

Abstract

Because planets are not expected to be able to form close to stars due to the high temperatures, it has been suggested that the observed close orbiting ($\sim 0.05$ AU) large mass planets ($\sim M_J$) might be mirror worlds -- planets composed predominately of mirror matter. The accretion of ordinary matter onto the mirror planet (from e.g. the solar wind from the host star) will make the mirror planet opaque to ordinary radiation with an effective radius $R_p$. It was argued in a previous paper, astro-ph/0101055, that this radius was potentially large enough to explain the measured size of the first transiting close-in extrasolar planet, HD209458b. Furthermore, astro-ph/0101055, made the rough prediction: $R_p \propto \sqrt{T_s \over M_p}$, where $T_s$ is the surface temperature of the ordinary matter in the mirror planet and $M_p$ is the mass of the planet (the latter dependence being the more robust prediction). We compare this prediction with the recently discovered transiting planets, OGLE-TR-56b and OGLE-TR-113b.