Technosignatures: Did WISE Detect Dyson Spheres/Structures Around Gaia-2MASS-selected Stars?
Soon after the release of the WISE all-sky catalogue of 500 million mid-infrared (IR) objects, suggestions were made that it could be used to search for extrasolar devices constructed by an advanced civilization to convert a significant fraction of their host star’s luminosity into useful work: “technostructures”, “megastructures” or “Dyson spheres/structures”, hereafter DSMs, whose inevitable waste heat would be seen by WISE at mid-IR wavelengths.
However, a trawl of several million potentially-habitable Gaia-detected stars for mid-IR-excess signatures is fraught with danger, due to both noise from such a large sample and, more importantly, confusion with the emission from dusty background galaxies. In light of a recent claim of seven potential DSMs in MNRAS, a brief rebuttal appeared on arXiv.
Further to this response, the relevance of WISE-detected galaxies is discussed in more detail, leading to a seemingly tight limit on the number and lifetime of DSMs, and indeed intelligent worlds, in the ~600-pc-radius region patrolled by Gaia. However, the detectability of DSMs is questioned: a DSM might extinguish its star at optical/near-IR wavelengths, and thus either not appear or appear anomalously faint in a stellar catalogue.
Moreover, a civilization advanced enough to construct a DSM is likely to be advanced enough to use countermeasures to mask its presence from us.
Andrew W. Blain
Comments: 6 pages. No figures. Submitted to MNRAS, possibly letters
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Popular Physics (physics.pop-ph)
Cite as: arXiv:2409.11447 [astro-ph.IM] (or arXiv:2409.11447v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2409.11447
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Submission history
From: Andrew Blain
[v1] Tue, 17 Sep 2024 10:41:46 UTC (19 KB)
https://arxiv.org/abs/2409.11447
Astrobiology, SETI, technosignature,
