The EXoplanet Climate Infrared TElescope (EXCITE): A balloon-borne mission to measure spectroscopic phase curves of transiting hot Jupiters

TL;DR

EXCITE is a balloon-borne infrared telescope designed to measure spectroscopic phase curves of hot Jupiters, aiming to understand their atmospheric composition and energy circulation patterns.

Contribution

This paper introduces the design, science goals, and initial flight performance of the novel EXCITE mission for exoplanet atmospheric characterization.

Findings

Successful engineering flight demonstration in 2024

Instrument's spectral coverage effectively captures key molecular signatures

Initial performance meets design expectations

Abstract

The EXoplanet Climate Infrared TElescope (EXCITE) is a balloon-borne mission dedicated to measuring spectroscopic phase curves of hot Jupiter-type exoplanets. Phase curve measurements can be used to characterize an exoplanet's longitude-dependent atmospheric composition and energy circulation patterns. EXCITE carries a 0.5 m primary mirror and moderate resolution diffraction-limited spectrograph with spectral coverage from 0.8--3.5 um. EXCITE is designed to fly from a long-duration balloon (LDB). EXCITE will observe through the peak of a target's spectral energy distribution (SED) and through spectral signatures of hydrogen and carbon-containing molecules. In this paper, we present the science goals of EXCITE, detail the as-built instrument, and discuss its performance during a 2024 engineering flight from Fort Sumner, New Mexico.