![Schematic diagram of the simulated architecture. It includes the segmented primary mirror, an APLC coronagraph with an apodizer, a focal plane mask and a Lyot stop, two deformable mirrors, and an out-of-band and a low-order Zernike wavefront sensor. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/JWST-telemetry.png?fit=1200%2C670&ssl=1)
[astro-ph.IM] We provide a quantification of the technological gap between the James Webb Space Telescope (JWST) and the Habitable Worlds Observatory (HWO) for the goal of exo-Earth imaging around Sun-like stars at the 10−10 raw contrast level.
We use JWST’s in-flight telemetry of the primary segmented mirror to simulate a JWST-like telescope equipped with a modern coronagraph instrument, inspired by the Roman Space Telescope (RST) Coronagraphic Instrument (CGI), featuring an Apodized Pupil Lyot Coronagraph and active deformable mirror wavefront control on a segmented, unobstructed, off-axis telescope.
We show that it can achieve around 10−10 raw contrast for very bright stars (brighter than magnitude 4) for fast control frequencies of 100 Hz, but that this level of control still lacks sufficient signal to correct JWST-amplitude errors for fainter stars.
We show that an improvement of a factor of ten in wavefront stability is sufficient to extend this capability to a 10−10 raw contrast across all considered control frequencies (1 Hz to 100 Hz), assuming no reaction wheel vibrations, for stars up to a magnitude of 11.
These results establish a new quantitative benchmark linking JWST’s demonstrated thermo-mechanical stability to HWO’s requirements, showing that active wavefront control relaxes the structural stability demands on the observatory, and identifying wavefront stability as the critical technological gap that must be closed for HWO to achieve its exo-Earth imaging goals.
Raphaël Pourcelot, Laurent A. Pueyo, Emiel H. Por, Marshall D. Perrin, Iva Laginja, Bryony Nickson, Sarah Steiger, Rémi Soummer, Rendal Telfer
Comments: 24 pages, 9 figures
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2608.28322 [astro-ph.IM] (or arXiv:2608.28322v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2608.28322
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Submission history
From: Raphaël Pourcelot
[v1] Fri, 28 Aug 2026 13:34:14 UTC (1,115 KB)
https://arxiv.org/abs/2608.28322
Astrobiology
