作者: Yan Bétrémieux , Lisa Kaltenegger
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摘要: Atmospheric refraction affects to various degrees exoplanet transit, lunar eclipse, as well stellar occultation observations. Exoplanet retrieval algorithms often use analytical expressions for the column abundance along a ray traversing atmosphere deflection of that ray, which are first order approximations valid low densities in spherically symmetric homogeneous isothermal atmosphere. We derive new formulae both these quantities, higher densities, and them refine validate tracing algorithm can be used arbitrary atmospheric temperature-pressure profiles. illustrate with simple profiles consequences our model different planets: temperate Earth-like Jovian-like planets, HD189733b, GJ1214b. find that, hot exoplanets, treatment does not make much difference pressures high 10 atmosphere, but it is important consider variation gravity altitude However, we atmospheres have an apparent scale height significantly smaller than their actual density at larger 1 amagat, thus increasing difficulty detecting spectral features originating regions. These denser regions form refractive boundary layer where abundances increases dramatically decreasing impact parameter. This mimics surface, none techniques mentioned above probe about 4 amagat on planets.