Astronomy & Telescopes

Review And Prospects Of Hot Exozodiacal Dust Research For Future Exo-Earth Direct Imaging Missions

By Keith Cowing
Status Report
astro-ph.EP
April 2, 2025
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Review And Prospects Of Hot Exozodiacal Dust Research For Future Exo-Earth Direct Imaging Missions
Sketch illustrating the distinction between hot and warm (HZ) exozodiacal dust and cold dust, as well as their location relative to other components of planetary systems. The Solar system is used as an approximate template, though the exact amount of hot dust in the Solar system is poorly known. Broad, gray rings represent dusty regions, while dotted, black rings represent belts of minor bodies (asteroids, Kuiper-belt objects). Possible planets and their orbits (thin black lines) similar to those in the Solar system are also shown. — astro-ph.EP

Hot exozodiacal dust is dust in the innermost regions of planetary systems, at temperatures around 1000K to 2000K, and commonly detected by near-infrared interferometry.

The phenomenon is poorly understood and has received renewed attention as a potential risk to a planned future space mission to image potentially habitable exoplanets and characterize their atmospheres (exo-Earth imaging) such as the Habitable Worlds Observatory (HWO).

In this article, we review the current understanding of hot exozodiacal dust and its implications for HWO. We argue that the observational evidence suggests that the phenomenon is most likely real and indeed caused by hot dust, although conclusive proof in particular of the latter statement is still missing.

Furthermore, we find that there exists as of yet no single model that is able to successfully explain the presence of the dust. We find that it is plausible and not unlikely that large amounts of hot exozodiacal dust in a system will critically limit the sensitivity of exo-Earth imaging observations around that star.

It is thus crucial to better understood the phenomenon in order to be able to evaluate the actual impact on such a mission, and current and near-future observational opportunities for acquiring the required data exist.

At the same time, hot exozodiacal dust (and warm exozodiacal dust closer to a system’s habitable zone) has the potential to provide important context for HWO observations of rocky, HZ planets, constraining the environment in which these planets exist and hence to determine why a detected planet may be capable to sustain life or not.

Steve Ertel, Tim D. Pearce, John H. Debes, Virginie C. Faramaz, William C. Danchi, Ramya M. Anche, Denis Defrère, Yasuhiro Hasegawa, Justin Hom, Florian Kirchschlager, Isabel Rebollido, Hélène Rousseau, Jeremy Scott, Karl Stapelfeldt, Thomas A. Stuber

Comments: Review paper based on work by ExoPAG SAG23 “The Impact of Exo-Zodiacal Dust on Exoplanet Direct Imaging Surveys” published in PASP
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Cite as: arXiv:2504.00295 [astro-ph.EP] (or arXiv:2504.00295v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2504.00295
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Journal reference: 2025PASP..137c1001E
Related DOI:
https://doi.org/10.1088/1538-3873/adb6d5
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Submission history
From: Steve Ertel
[v1] Mon, 31 Mar 2025 23:46:49 UTC (3,166 KB)
https://arxiv.org/abs/2504.00295
Astrobiology,

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) 🖖🏻