Transits and secondary eclipses of HD 189733 with Spitzer

TL;DR

This paper uses Spitzer observations to measure transit timing and secondary eclipse variations of HD 189733, improving constraints on potential additional planets and atmospheric properties.

Contribution

It presents high-precision infrared transit and eclipse measurements, offering new limits on secondary planets and atmospheric absorption features.

Findings

High-accuracy transit times achieved with Spitzer

Constraints on secondary planets of Mars mass in resonance

Wavelength-dependent atmospheric absorption limits improved

Abstract

We present limits on transit timing variations and secondary eclipse depth variations at 8 microns with the Spitzer Space Telescope IRAC camera. Due to the weak limb darkening in the infrared and uninterrupted observing, Spitzer provides the highest accuracy transit times for this bright system, in principle providing sensitivity to secondary planets of Mars mass in resonant orbits. Finally, the transit data provides tighter constraints on the wavelength- dependent atmospheric absorption by the planet.