Refraction in exoplanet atmospheres: Photometric signatures, implications for transmission spectroscopy, and search in Kepler data

摘要: Refraction deflects photons that pass through atmospheres, which affects transit light curves. thus provides an avenue to probe physical properties of exoplanet atmospheres and constrain the presence clouds hazes. In addition, effective surface can be imposed by refraction, thereby limiting pressure levels probed transmission spectroscopy. The main objective paper is model effects refraction on photometric curves for realistic planets explore dependencies atmospheric parameters. We also under circumstances spectra are significantly affected refraction. Finally, we search signatures in residuals Kepler data. use Hui & Seager (2002) compute deflection angles curves, allowing us parameter space properties. observational performed stacking large samples from Kepler. find out-of-transit shoulders most easily observable features, reach peak amplitudes ~10 parts per million (ppm) around Sun-like stars. More typical a few ppm or less Jovians at sub-ppm level super-Earths. Interestingly, signal-to-noise ratio any orbiting hosts expected similar red dwarfs. maximum depth spectroscopy not limited weakly lensing planets, but incidence vary strongly planets. no signs features stacked agreement with our predictions.