![Waste-heat temperature–luminosity phase space. Existing midinfrared searches occupy the warm band (orange); cold computational radiators fall in the far-infrared/submillimetre band (green) towards the CMB floor. Grey lines show 345-GHz flux-density contours for a source at 100 pc, from equation (10), which is linear in the fractional waste-heat luminosity 𝑓 on the vertical axis; the figure thus covers partial swarms and complete spheres (𝑓 = 1) alike. Markers indicate a complete 1 L⊙ cold sphere, the level of the archival debris-survey limits (Section 6.1), and the domain of warm mid-infrared searches. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Slysh.png?resize=1200%2C720&ssl=1)
[astro-ph.IM] Searches for Dysonian waste heat have operated almost exclusively in the mid-infrared and are therefore sensitive primarily to technology radiating at 100-600K. We argue that mature, computation-dominated civilisations may […]
Dyson Sphere
![Where the Dyson sphere on and off fits of M77 differ most, and how new photometry changes the comparison. In each panel, the upper sub-panel shows the median posterior AGENT-on (solid red) and AGENT-off (dashed blue) model spectra with shaded 16–84% posterior bands and the fitted photometry overplotted (open black circles), while the lower sub-panel shows the percent deviation of the AGENT-on model relative to the AGENT-off model, with the shaded band giving the 1σ uncertainty propagated in quadrature from the two independent fits. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-G.png?resize=1200%2C713&ssl=1)
Posted inSETI & Technosignatures
The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. V. When Galaxies Glow with Industry
[astro-ph.GA] We present the most robust stellar population synthesis (SPS)-based search for galaxy-spanning technological waste heat to date, applied to 129 nearby galaxies spanning a wide range of spectral energy […]
![Blackbody spectra derived from the 𝑇eff of the Dyson sphere candidates A to J throughout the wavelength range of 10 to 1000 microns together with the detection thresholds of telescopes Akari (Murakami et al. 2007), IRAS (Neugebauer et al. 1984), the ALMA 12∼m array6 and JWST/MIRI. In the case of JWST, both broadband imaging and spectroscopic limits (based on the LRS Slit or MRS7observations) are shown. In the case of JWST and ALMA, all limits refer to 5𝜎 confidence in 1 hour exposure time (where exposure times refer to observations per filter in the case of imaging; per band in the case of ALMA spectroscopy; per channel in the case of JWST/MIRI MRS spectroscopy and for the entire plotted wavelength range in the case of JWST/LRS spectroscopy). As can be seen, all candidates are detectable throughout some part of the wavelength coverage of JWST. The inset shows a zoom-in on the part of the spectral energy distribution that may be detectable with ALMA for four of the candidates (A, G, I and J). -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Project-Hephaistos-1.png?resize=1200%2C720&ssl=1)
Posted inSETI & Technosignatures
Project Hephaistos — III. Characterizing Anomalous Infrared Sources Identified As Dyson-sphere Candidates
[astro-ph.SR] The infrared-flux excess of stars harbouring Dyson spheres represent one potential technosignature of extraterrestrial intelligence.
![The Rapid ASKAP Continuum Survey (RACS) radio images of radio sources associated with candidates A (J1245-2652, top row) and B (J0356-4031, bottom row) are shown at three frequencies: 887.5 MHz (left), 1367.5 MHz (centre), and 1655.5 MHz (right), with each panel covering a field of view of 65" × 65" . White ellipses show the PyBDSF source fits from the RACS catalogues, with thick solid lines indicating the fits at the frequency of the image, while thin dashed lines show fits from the other radio frequencies for comparison. Large blue crosses (×) mark radio source positions for the corresponding frequency, and small blue plus signs (+) indicate positions at other frequencies. The red stars represent the Gaia positions propagated to the corresponding RACS observation epochs using the measured proper motions. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Archival-Diagnostics.png?resize=1200%2C720&ssl=1)
Posted inSETI & Technosignatures
Archival Diagnostics for Potential Background Contaminants Of Project Hephaistos Dyson Sphere Candidates
[astro-ph.SR] We report on the diagnostic inspection of nine Project Hephaistos Dyson Sphere candidate M-dwarfs based on archival data. By comparing the Gaia positions, propagated to the AllWISE epoch, with […]
![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?resize=1200%2C720&ssl=1)
Posted inSETI & Technosignatures
Project Hephaistos — IV. James Webb Space Telescope Observations of Two Dyson Sphere Candidates
[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 […]
Posted inBiosignatures & Paleobiology, Intelligence & Language, SETI & Technosignatures, Status Report
Dust To Dust: Prospects For Passive Technosignatures As Relics Of ETI
Technological societies are separated in time, not just space — that is the lesson of the Drake equation.
Posted inAstronomy & Telescopes, Conferences and Meetings, Intelligence & Language, Interstellar, Nanotechnology & SynBio, Press Release, SETI & Technosignatures
The Dyson Minds 2025 Workshop: SETI around Black Holes
The Dyson Minds 2025 Workshop, held at the Center for Brains, Minds & Machines at MIT and organized by Penn State, MIT, and The Ultraintelligence Foundation, brought together researchers in […]
Posted inAstronomy & Telescopes, Biosignatures & Paleobiology, Intelligence & Language, Interstellar, SETI & Technosignatures, Status Report
Undetected Past Contacts With Technological Species: Implications For Technosignature Science
In the search for extraterrestrial intelligence (SETI), the highly incomplete sampling of the technosignature search space is often considered as a plausible explanation for the persistent lack of detections over […]
Posted inAstronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Interstellar, SETI & Technosignatures, Status Report
WISE/CatWISE Constraints On Dysonian Waste-Heat Technosignatures In Nearby Galaxies
We search for galaxy-scale (Dysonian) waste heat in the mid-infrared using WISE. Starting from the 2MASS Redshift Survey (2MRS), we cross-match to CatWISE2020 and AllWISE, apply standard MIR AGN/starburst vetoes […]
Posted inAstronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Press Release, SETI & Technosignatures
Microlensing Signatures Of Dyson Sphere-like Structures Around Primordial Black Holes As Technosignatures Of Extraterrestrial Advanced Civilizations
We investigate the microlensing detectability of extraterrestrial technosignatures originating from Dyson sphere – like structures, such as Dyson Swarms surrounding primordial black holes (PBHs).