The Implementation of Stellar Occultation Light Curve Modelling for Arbitrary Planetary Atmospheric Structures and the Analysis of Pluto’s Occultation Light Curves and Its Atmosphere

Abstract

For decades, the analyses of stellar occultation light curves have been the most efficient method to study atmosphere of small solar system bodies. The variation in stellar flux due to the refraction in planetary atmosphere is directly related to the temperature profile of the planetary atmosphere. In this thesis, we implemented the occultation model derived by Chamberlain and Elliot (1997) [2], which is compatible with any occulting body with arbitrary temperature profile. The implementation was used to analysed Pluto occultation light curve of the star P384.2 on June 12, 2006. The result from the fit suggested that, if Pluto’s temperature profile in June 2006 were isothermal, it profile would be consistent with the surface temperature of 74.2 ± 1.4 𝐾. The best fit light curve from the isothermal model, however, expressed some inconsistency near the closest approach. The result, therefore, suggested that neither isothermal model nor the model with temperature gradient are sufficient to describe Pluto’s temperature profile. More complicated temperature profiles should be considered, which are enable with this implementation.