Exoplanet Atmosphere Retrieval from Multifractal Analysis of Secondary Eclipse Spectra

TL;DR

This paper introduces a model-free multifractal analysis method to study exoplanet atmospheres using secondary eclipse spectra, providing insights into atmospheric structure and dynamics without relying on prior models.

Contribution

The paper extends a multifractal analysis technique to secondary eclipse spectra, enabling model-free atmospheric characterization during exoplanet emission observations.

Findings

Successfully applied to Spitzer data for HD189733b

Provides information on atmospheric flows and energy redistribution

No reliance on prior atmospheric models

Abstract

We extend a data-based model-free multifractal method of exoplanet detection to probe exoplanetary atmospheres. Whereas the transmission spectrum is studied during the primary eclipse, we analyze the emission spectrum during the secondary eclipse, thereby probing the atmospheric limb. In addition to the spectral structure of exoplanet atmospheres, the approach provides information to study phenomena such as atmospheric flows, tidal-locking behavior, and the dayside-nightside redistribution of energy. The approach is demonstrated using Spitzer data for exoplanet HD189733b. The central advantage of the method is the lack of model assumptions in the detection and observational schemes.