![Images in the JWST/MIRI F560W, F1000W and F1500W filters (central wavelength ≈ 5.6, 10 and 15 𝜇m) of candidates D (first row) and E (second row). White stars mark the Gaia positions of the M dwarfs, which in both cases are seen to be located ≈ 1 arcsec from the centres of background galaxies. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Project-Hephaistos.png?fit=1200%2C674&ssl=1)
[astro-ph.GA] We report on JWST/MIRI imaging and spectroscopy of two M-dwarf stars previously singled out by project Hephaistos as potential Dyson-sphere candidates (their candidates D and E) due to the presence of excess flux at mid-infrared wavelengths.
We find that the infrared excess does not originate from Dysonian megastructures, or other radiation mechanisms close to these stars, but from background galaxies projected within ∼1 arcsec of the M dwarfs, thereby confusing previous mid-infrared photometry obtained with the WISE telescope.
The candidate D background galaxy lies at redshift z≈0.9, appears point-source dominated in imaging and has a mid-infrared spectrum consistent with being a Hot Dust Obscured Galaxy (Hot DOG).
The candidate E background galaxy lies at z≈0.4, displays an extended morphology with bright knots and a spectrum consistent with a dusty starburst.
Erik Zackrisson, Arjan Bik, Anita Ali Asgar, Olivia Curtis, Jason T. Wright, Tongtian Ren, Roberto J. Assef, Andrew Blain, Alexis Brandeker, Michael A. Garrett, Uma Gorti, Andreas J. Korn, Priyatam K. Mahto, Armin Nabizadeh
Comments: 13 pages, 9 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2607.09460 [astro-ph.GA] (or arXiv:2607.09460v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2607.09460
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Submission history
From: Erik Zackrisson
[v1] Fri, 10 Jul 2026 14:32:43 UTC (887 KB)
https://arxiv.org/abs/2607.09460
Astrobiology, SETI, Technosignature, Astronomy,
