A New Atmospheric Model for HD 189733 b

TL;DR

This paper introduces a new 2D atmospheric model for exoplanets, applied to HD 189733 b, revealing turbulent flows and temperature variations that explain observed light curve fluctuations.

Contribution

The paper presents a novel 2D hydrostatic atmospheric model specifically designed for exoplanets, demonstrating its effectiveness on HD 189733 b with results consistent with observations.

Findings

Development of a 2D hydrostatic atmospheric model for exoplanets

Simulation shows turbulent supersonic flows with ~5 km/s wind speeds

Chaotic temperature variations cause observable light curve fluctuations

Abstract

We have developed a new two-dimensional hydrostatically-balanced isobaric hydrodynamic model for use in simulation of exoplanetary atmospheres. We apply this model to the infrared photosphere of the hot Jupiter HD 189733 b, for which an excellent 8-micron light curve has been obtained. For reasonable parameter choices, the results of our model are consistent with these observations. In our simulations, strongly turbulent supersonic flow develops, with wind speeds of approximately 5 km/s. This flow geometry causes chaotic variation of the temperature distribution, leading to observable variations in the light curve from one orbit to the next.