Astronomy & Telescopes

Rapid Characterization Of Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager (ETSI)

By Keith Cowing

Status Report

astro-ph.IM

March 11, 2025

Filed under astro-ph.IM, astronomy, atmosphere, ETSI, exoplanet, Hubble, imaging, Spectroscopy

Rapid Characterization Of Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager (ETSI) — Section view of the ETSI optics and detectors. The telescope focal plane is to the left of the image. Light enters the collimator and is split into two channels by the multi-chroic which is located at the pupil. Identical prisms disperse the light which is then further filtered to sharpen the transmission cut on/off transitions and imaged with identical cameras onto sCMOS detectors. — astro-ph.IM

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=λ/δλ∼20.

ETSI requires only moderate telescope apertures (∼2 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.

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

Comments: 33 pages, 17 figures, published in JATIS
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2503.03931 [astro-ph.IM] (or arXiv:2503.03931v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2503.03931
Focus to learn more
Journal reference: Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 10, Issue 4, 045005 (December 2024)
Related DOI:
https://doi.org/10.1117/1.JATIS.10.4.045005
Focus to learn more
Submission history
From: Luke Schmidt
[v1] Wed, 5 Mar 2025 22:05:40 UTC (6,671 KB)
https://arxiv.org/abs/2503.03931
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter