[astro-ph.IM] Techniques for identifying radio beacons transmitted by extra-terrestrial civilizations are well advanced.
Intelligence & Language
![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)
Posted inSETI & Technosignatures
Slysh Haloes: The Waste Heat Of Cold Computing As A Submillimetre Technosignature
[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 […]
Posted inSETI & Technosignatures
Gaia DR3 Limits on Stellar Engine Technosignatures in Nearby Stars
[astro-ph.GA] An operating stellar engine that transfers momentum to its host star could produce an approximately persistent transverse acceleration during the Gaia Data Release 3 (DR3) observing epoch.
![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 […]
![Ciara Sypherd, Ph.D. candidate in bioengineering (Pil Rosted Christensen) [Harvard]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Decoding-Animal.png?resize=1200%2C721&ssl=1)
Posted inSETI & Technosignatures
Decoding Animal Communication With AI
[Harvard] Fresh off degrees in astrobiology and aerospace engineering at Arizona State University, Ciara Sypherd took on a one-year research position at the University of Copenhagen to study how neural […]
![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.
Posted inSETI & Technosignatures
Breakthrough Listen’s Automated Commensal Technosignature Survey With MeerKAT
[astro-ph.IM] The search for extraterrestrial intelligence (SETI) is an ongoing effort to detect technosignatures, evidence of technologically capable life beyond Earth. Conducting a comprehensive SETI programme requires a large amount […]
Posted inSETI & Technosignatures
Could Alien Signals Be Hiding On A Different Radio Channel?
[RAS] Astronomers searching for signs of extraterrestrial intelligence may have been missing alien signals in part of the radio spectrum that has not recently been explored.
![Simulated light curve for a periodic laser beacon at fpulse = 413 Hz at d = 15 pc observed with a Dtel = 1 m telescope at a cadence of 10 µs. The upper panels show a short segment of the noiseless pulse signal (left) and the corresponding signal including the estimated noise contributions (right). The bottom panel shows the integrated folded pulse profile after combining 108 pulses, resulting in an expected SNR of approximately 5.99. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-Interstellar-Laser.png?resize=1200%2C716&ssl=1)
Posted inSETI & Technosignatures
The Interstellar Laser Beacons Hypothesis and the Cosmic Lighthouses Project
[astro-ph.IM] In this paper, we argue that in a realistic, resource-limited scenario senders whose intent is to maximize successful communication at the lowest cost will utilize very long-lived, pulsed beacons.
![Conservative CW mitigation demonstrated on a fully synthetic wideband radio dataset with realistic detector features. (a) Frequency spectrum before and after mitigation. Red shaded regions indicate the three cataloged anthropogenic CW tones at 137, 405, and 450 MHz (representing satellite downlinks, weather balloon telemetry, and South Pole station communications, respectively). These tones are removed via least-squares time-domain sine subtraction as described in the text. The orange dotted line marks an uncataloged narrowband feature at 285 MHz that is successfully preserved. (b) Time domain trace of the same waveform shown in panel (a), zoomed in to show the effect of mitigation around an injected nanosecond-scale broadband transient (dashed black line). The raw simulated trace before mitigation (light red line) is heavily obscured by CW interference. After subtraction of the cataloged tones, the mitigated trace (solid green line) shows significantly reduced coherent CW contamination, successfully recovering the underlying broadband impulsive signal and preserving both its original shape and temporal structure. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Methodological-Synergies.png?resize=1200%2C720&ssl=1)
Posted inSETI & Technosignatures
Methodological Synergies Between Technosignature And UHE Neutrino Searches
[astro-ph.IM] Radio technosignature searches and radio-based ultra-high energy (UHE) neutrino experiments address different scientific questions, but share a closely related data analysis problem: identifying rare signals of unknown morphology within […]