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arXiv · 2503.03931

Rapid characterization of exoplanet atmospheres with the Exoplanet Transmission Spectroscopy Imager (ETSI)

Luke M. Schmidt·Ryan J. Oelkers·Erika Cook·Mary Anne Limbach·Darren L. DePoy·Jennifer L. Marshall·Landon Holcomb·Willians Pena·Jacob Purcell·Enrique Gonzalez Vega
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Abstract

The Exoplanet Transmission Spectroscopy Imager (ETSI) amalgamates a low resolution slitless prism spectrometer with custom multi-band filters to simultaneously image 15 spectral bandpasses between 430 nm and 975 nm with an average spectral resolution of $R = \lambda/\delta\lambda \sim 20$. ETSI requires only moderate telescope apertures ($\sim2$ m) and is capable of characterizing an exoplanet atmosphere in as little as a single transit, enabling selection of the most interesting targets for further characterization with other ground and space-based observatories and is also well suited to multi-band observations of other variable and transient objects. This enables a new technique, common-path multi-band imaging (CMI), used to observe transmission spectra of exoplanets transiting bright (V$<$14 magnitude) stars. ETSI is capable of near photon-limited observations, with a systematic noise floor on par with the Hubble Space Telescope and below the Earth's atmospheric amplitude scintillation noise limit. We report the as-built instrument optical and optomechanical design, detectors, control system, telescope hardware and software interfaces, and data reduction pipeline. A summary of ETSI's science capabilities and initial results are also included.

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Luke M. Schmidt, Ryan J. Oelkers, Erika Cook, Mary Anne Limbach, Darren L. DePoy, Jennifer L. Marshall, Landon Holcomb, Willians Pena, Jacob Purcell, Enrique Gonzalez Vega. 2025-03-05. Rapid characterization of exoplanet atmospheres with the Exoplanet Transmission Spectroscopy Imager (ETSI). https://doi.org/10.1117/1.jatis.10.4.045005

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