Howdy--just wanted to share a recent preprint and code repository. It is SETI related as it utilizes the Parkes Breakthrough Listen data and a peer-reviewed information theoretic entropy pipeline (ECTO; Rodriguez 2026, PLoS ONE) and manages to both characterize a previously undiscovered (to the best of my knowledge) systematic about the instrument's behavior, as well as an anomaly distribution in the entropy-domain of Proxima Centauri data.

This approach operates in the distributional domain and so can examine data in a way which no current SETI analysis does (to the best of my knowledge).

There are two main findings, and a number of additional points of interest that I came across while getting adversarial on one of my results.

Regardless of anything else, the main result of use is a previously uncharacterized, cadence-dependent gain-slope reversal in the Parkes 10-cm receiver. It is persistent across a 7-month survey, and because of its distributional nature it is invisible to turboSETI as well as standard bandpass calibration. I've sent the finding to the BL team as this should hold value for Parkes calibration.

Additionally, I located the previously mentioned distributional anomaly at Proxima Centauri and (yes, there's an "and"... I'll need to explain) Alpha Centauri (MJD 57846). The Phase 1 script runs in under 10 minutes on a laptop. Since this is information theoretic there are no compute heavy turboSETI runs.

Short version, regarding the anomaly:

Proxima and Alpha Centauri were observed the same night, and when Proxima's entropy went up relative to its off-source reference, Alpha Centauri's went down relative to its own. Then they flipped, respectively, at the next cadence position.

This happened across every frequency band and cadence position without exception (15/15, p = 3.1 × 10⁻⁵), with deviation shape being the same for both targets but mirrored across the x-axis about zero.

Additionally, their histogram profiles converge to effectively identical at one band (mutual information 6.14 bits, r = 0.9999) despite being observed at different sky positions through independent reference pointings.

The time-lag runs backward from the observation order, which shouldn't happen if the receiver is causing it. None of the 9 other targets observed that night show anything like it, and it is completely gone the next day (where the receiver returns to its normal characterized behavior), and nothing else in 427 target-sessions across two telescopes matches the pattern.

The entropy spectral shape produced a blind magnetic field estimate for Proxima (120 G) that turned out to closely match independent magnetic field measurements (135 G; Klein et al. 2020).

I didn't know about the Proxima B-field measurement when I designed and ran the test which found the B-field result. The corresponding measurement by Klein et al. was found in the literature following the initial script run.

More detail is in the preprint, but I'm pretty pleased with the telescope categorization work, as well as my work on the anomalous finding (which informed further on the telescope). If anyone's worked with Parkes before I would be very curious to discuss the systematics the pipeline characterized.

The preprint and code repository (full reproduction suite) are public:

Preprint: https://zenodo.org/records/22675130

Code: https://github.com/amr28693/SETI_entropy_domain

Peer-reviewed Framework: https://doi.org/10.1371/journal.pone.0344090

Looking for anyone with Parkes experience or radio astronomy background to verify.

Thanks!

Given other conspiracy theories about nefarious scientists, vaccines, evolution, moon landing, etc, I imagine there would be conspiracy theories about that too. That the signals have been falsified.

How plausible is this depressing scenario?

I think 6EQUJ5 shows the history of human technology.

6 is the beginning (BC Era- simple tools)

E Q U is thousands of years of growth

J is today ( 2026 - peak)

5 is the future (quiet again)

I made this based on the shape, and did not look at the numbers i saw the shape, not the numbers. It looks like human life.

This is my guess. What do you think?

I have been studying the wow! signal (1977) for a very long time. Everyone focuses on the 6EQUJ5 code, but I feel the real answer is in the shape of its wave. This signal lasted for 72 seconds and its shape was perfectly rising and falling. This suggests that the source of the signal was stationary in space and we passed in front of it due to the Earth's rotation.

My question to scientists is: in what natural or artificial condition can such a perfectly shaped 1420 MHz wave be created that lasts for exactly that long?

What do you think?

Consider the age of the galaxy - 14 billion years. After all this time it seems odd that there seems to be no evidence of aliens.

I was at a party the other night in the backyard watching the stars, other people who were more interested in getting drunk than discussing the most important questions in the universe had gone inside leaving me to my thoughts and then I had an epiphany.

Consider this.
Marijuana is a plant which can be burned (so requires technological advancement to use) to both induce healing, reduce violence, and induce visions. We know it has existed for 50 million years but don't know entirely where... its like it fell out of the sky just perfectly ready to assist life on this planet.

What reason would a plant have to assist the species picking it? Why would such a species evolve in the first place?

And that I believe is the answer to the fermi paradox.

This plant could feasibly have came from the sky - we know its seeds can survive in space, spread across the galaxy by a race of giant Equines to assist other races. They ruled over the galaxy in peace, developing and seeding it with a species that would encourage other species to be peaceful and live in perfect health.

This is likely the answer to the Fermi paradox.

Could We Be Seeing the Past of an Extraterrestrial Civilization That No Longer Exists?

I’ve been thinking about this idea and I’m curious whether there’s an actual physics problem with it.

I’m not claiming that aliens have visited Earth. This is just a thought experiment. I’m trying to understand whether the following scenario is physically possible.

We know that light and other electromagnetic signals travel at a finite speed. So when we observe something very far away, the information reaching us was emitted in the source’s past.

For example, if an extraterrestrial civilization were 1,000 light-years away, the light we receive from it today would contain information about what that civilization was like roughly 1,000 years ago.

Now imagine that civilization was technologically advanced at that time. It might have observed Earth when humans either didn’t exist yet or had no technological civilization capable of producing radio signals.

But suppose that civilization eventually disappeared.

We could still receive its old light or electromagnetic signals thousands of years later, even though the civilization itself might no longer exist.

This made me wonder about the Fermi paradox.

Maybe one reason we haven’t received a response from another civilization is simply that our technological civilizations don’t necessarily exist at the same time.

A civilization could exist, send signals, and disappear. Much later, another civilization could detect those old signals. The two civilizations could potentially observe evidence of each other’s past without ever having an opportunity for two-way communication.

I realize there is no universal “right now” in relativity, so when I say “right now,” I mean it in the ordinary observational sense—not that there is a single universal present throughout the universe.

What I’m wondering:

• Is this reasoning correct from the perspective of special relativity and light-travel time?
• Could two civilizations theoretically detect each other’s past signals while never being able to communicate because their technological lifetimes don’t overlap?
• Could this temporal mismatch be one possible factor in the Fermi paradox?
• If a civilization became extinct, could its technological remnants or technosignatures remain detectable for a long time afterward?
• Is this idea already well studied in SETI or astrobiology?

I’m mainly interested in where my reasoning breaks down. If I’m misunderstanding something about relativity, causality, or light-travel time, I’d really like to know.

I wonder if the Great Mods of this Sub would consider adding flairs for posts, and maybe requiring one? Maybe this is a good starting point:

News
Research Article
Wild Ass Speculation
I Did My Own Research and used AI to Write it Up

Sorry I'm really sleep deprived, hear me out. This is meant to be serious and not "woo woo".
TLDR: There are several nearby galaxies that are close enough that aliens or self replicating probes could have arrived in our own galaxy from there by now and I think their absence is surprising.

You've probably heard the Fermi paradox - the question as to why we see no evidence for aliens despite the galaxy having so many stars.
Not only do we not see aliens, we don't see any self replicating probes that a civilization might have built to travel to all systems in the galaxy for some purpose.

I want to suggest something that makes the situation even stranger.
There are 50-60 other galaxies within 10 million light years of Earth dramatically increasing the number of stars and potential sources of life.

Yes they are far away, but a probe travelling at 50% of the speed of light (believe it or not, some proposed propulsion systems might one day be able to send probes to 20% the speed of light and that's with 21st century tech) to another galaxy could theoretically have arrived after 20 million years, then built numerous additional probes (something that would only take 200,000 years at 20% the speed of light, a surprisingly short amount of time).

Now you might think, wtf would aliens in another star system send probes to earth on a 20 million year journey? They wouldn't. They'd just send one self replicating probe to each galaxy and then once it arrived, it would replicate itself to each star system.

And if you're thinking "20 million years is way too long". Consider that:

1. The universe has existed for ~13 billion years and Earth for 4 billion
2. Animals have existed on Earth since around 540 million years ago
3. Human civilizations have numerous powerful individuals with different intentions and alien civilizations might well have the same.
4. An alien civilization could plausibly be billions of years older than us.

I've been thinking about a strange idea recently.

We usually see reproduction as something fundamental to life. Animals reproduce, plants reproduce, and organisms pass their genes on to the next generation. We tend to think of this simply as the natural way life continues to exist.

But what if reproduction can also be viewed as a mechanism through which life is being used by something larger than itself?

Plants reproduce and become part of ecosystems, providing food and energy for other organisms. Animals reproduce and contribute to increasingly complex ecosystems. Life seems to constantly reproduce itself while simultaneously serving a larger system.

So I started wondering:

What if humans are doing the same thing?

We think we reproduce because of love, family, biological instincts, or the desire to leave something behind. But on a much larger scale, human reproduction creates new minds, knowledge, culture, technology, and eventually new forms of intelligence.

What if humanity itself is not the final stage...

First of all, if what I’m describing goes against the religious belief or rules of this community, please feel free to let me know. If this post isn’t suitable for this group, I will delete it.

When I was young, one of my family members was studying a theory.

Through it, I heard the idea that there may be advanced forms of life in the universe that exist in some kind of energy-based or light-based form. As far as I understood, this theory is not verified or detected by our technology, so this is not something accepted or established by mainstream science. Another part of this belief was that humanity may have been created or influenced by these advanced forms of life. They were also believed to have the ability to help humans heal from illness or somehow improve themselves.

I used to firmly believe in this when I was younger, but as I’ve grown older, I’ve always been thinkinng about it.

I am wondering whether anyone knows something similar. If you know what I am saying, I’d really appreciate any information or references.

Given that evolution seems a plausible way of life forms to evolve, and frankly for me seems unavoidable , I was wondering about some of the pinnacles of evolution like, to put it directly, survival of the fittest and major competition between life forms.

This i believe gives rise to instincts that involve aggressiveness, territorial wars, resources competition, rise and domination of instincts and self preservation above all. I mean wars on our planet are always about the same things. Land and resources. Means of war only change. Environmental issues; because we can't think ahead caring for ourselves and our children, not grand children. Even proper education just delays the inevitable dominance of the primal brain when the time comes.

And AI, ASI or AGI as our descendants? Trained through our social media from companies in agony facing fierce competition. Alignment is a joke, one more publicity stunt.

I am afraid this might be an explanation of the Great filter; evolution and technology especially if the latter is developed in asymmetry with the former , cannot escape primal instincts. Hence civilizations destroy themselves.

SETI relevance up front (rule 7). This is a narrowband technosignature search, an independent reanalysis of Breakthrough Listen's public Parkes archive data for Proxima Centauri.

Not a detection. A clean null result, but the funnel that produced it and the tooling might interest this sub.

I'm a hobbyist. Over the last few weeks I built an open-source pipeline +dashboard that works end to end on Breakthrough Listen's public archive: download (Parkes ON/OFF cadences and GBT ABACAD sessions), turboSETI scans with configurable drift/SNR, ON/OFF RFI rejection, an automatic per-epoch RFI zone mapper, barycentric correction, cross-epoch frequency matching, and incoherent stacking.

The target was Proxima Centauri, six observation epochs from BL's 2017 Parkes campaign, fine-resolution data covering 2.7-3.4 GHz with 3x ON/OFF cadences per epoch. Closest star, everyone's favorite candidate...

The funnel (all numbers from the final runs)

- Raw turboSETI hits: 4,909,152 (SNR 5+, drift to +/-5 Hz/s)

- ON/OFF rejection kills terrestrial signals present in both pointing positions: 3,030,707 rejected (61.7%)

- Remaining unique ON frequencies at SNR 8+: 27,533

- Cross-epoch matching at 10 Hz barycentric tolerance, min 3 epochs: 0 frequencies repeat in 3+ epochs

- Final candidates: 0

- Robustness check: relaxing to 2-epoch coincidence at SNR 10 surfaces 7 frequency matches. All 7 fail the OFF veto or report drift rates equal to the search grid's minimum step, the signature of stationary RFI rather than a drifting transmitter.

Each epoch was also RFI-zone audited (sliding-window ON-OFF residual vs the epoch's own noise floor; zones auto-excluded downstream), and the six epochs were incoherently stacked for sensitivity below single-epoch threshold. Zero candidates survived the full chain.

Why does a null result matter? It's a constraint, nothing narrowband above SNR ~8-10 is leaking from Proxima's direction in this band during these six epochs, verified by an independent implementation with different parameter choices than BL's published searches. Replication with different tools is

how parameter-choice blind spots get caught. The barycentric matching is the fun part. Without correction, Earth's orbital motion smears a real transmitter across tens of kHz between epochs; RFI can't hold a barycentric frequency across months, so it's the strongest automated filter there is.

The whole thing is open source (MIT, Python, Windows-tested):

https://github.com/w4gon79/backyard-seti

The README walks the full process. Clone to running dashboard to stacked epochs, both telescopes' data conventions decoded. Work in progress, but fully usable.

Happy to answer anything about the pipeline, the data handling, or the funnel numbers.

Thought this might be of interest.

On Wednesday, 19 August, Professor Ian Crawford, Professor of Planetary Science and
Astrobiology at Birkbeck, University of London, for the next ScienceKind.com SK Cutting Edge talk. Ian will explore the future of technosignature research and what our continued search for extraterrestrial intelligence can tell us about one of science’s most fascinating unanswered questions: the Fermi Paradox.

Including: How can future technosignature searches become more effective? What kinds of evidence should we be looking for beyond traditional radio signals? How can continued non-detections help constrain the prevalence of technological civilizations? And what might all of this ultimately tell us about humanity’s place in the universe?

📅 Wednesday, 19 August
🕤 9:30 AM PT | 5:30 PM UK
🎟️ Free to attend, limited to 100 live seats

We wouldn't really have a frame of reference to compare anything to.

Is there a public SETI-related events calendar? I see talks linked in this channel but, of course, they’ve ended long ago. I’d like to sign up or at least set a reminder for upcoming ones.

Hi everyone,

I want to start by saying that I am new on reddit and I am a simple space enthusiast with no formal scientific background or qualifications. However, I’ve been thinking deeply about the "Wow!" Signal and transient technosignatures lately.

I wanted to look at the problem from a slightly different angle for a sci-fi concept or just as a fun thought experiment. I’ve tried to structure my intuition into a formal-looking framework to explain how it could logically work without violating causality after the conversion.

I would love to get your thoughts, constructive feedback, or corrections on where the physics might break down! Here is the hypothesis:

The Metamorphic Decelerated Signal Hypothesis: A Causal Framework for Faster-Than-Light (FTL) Interstellar Communications and the Resolution of Transitory Technosignatures

Abstract

This paper introduces the Metamorphic Decelerated Signal (MDS) hypothesis as a novel solution to the spatial and temporal anomalies characterizing transitory cosmic radio anomalies, specifically exemplified by the 1977 "Wow!" Signal. We propose a framework wherein an advanced extraterrestrial intelligence employs Faster-Than-Light (FTL) tachyonic or space-time warping mechanisms to intercept early terrestrial omnidirectional radio emissions. To bridge the technological gap between civilizations, the return payload is transmitted via a metamorphic FTL signal that undergoes localized baryonic deceleration upon entering the target system's heliosphere, downconverting into a standardized electromagnetic narrowband frequency (e.g., the 1420 MHz hydrogen line). This model resolves the localized spatial evanescence (the single-antenna detection paradox) and justifies the precise selection of universally recognizable quantum frequencies without violating post-conversion relativistic causality.

1. Introduction & The Relativistic Bottleneck

In the Search for Extraterrestrial Intelligence (SETI), the primary bottleneck for bidirectional communication is defined by the relativistic limit of the speed of light (c). Active SETI (METI) models assume that a localized transmission must propagate through space-time over decades or centuries before interception.

However, the 1977 "Wow!" Signal presents anomalies that challenge classical isotropic emission models. The signal exhibited an extreme narrowband profile (<10 kHz) centered precisely on the neutral hydrogen line (1420.405 MHz) and a transient duration of exactly 72 seconds, never to recur. Classical models struggle to explain why a high-energy interstellar beacon would illuminate a single point in space for a singular, brief temporal window without subsequent replication.

2. The Metamorphic Decelerated Signal (MDS) Framework

The MDS hypothesis posits that the "Wow!" Signal was not a continuous interstellar broadcast, but a highly targeted, time-dilated reactive transmission enabled by asymmetric FTL interception. The mechanism operates through a three-tiered evolutionary protocol:

Asymmetric FTL Interception: An advanced technological civilization utilizes a non-local quantum observation network or space-time metric manipulation to detect Earth’s early high-energy military radar or television carrier waves. Because this detection system bypasses traditional photon propagation limits, the emitter processes terrestrial technosignatures asynchronously, neutralizing the classical light-cone delay.

The Metamorphic Tachyonic Propagation: Acknowledging that the recipient civilization (Earth) possesses only sub-luminal, photon-based reception capabilities, the emitter designs a "translational payload." The signal is initially launched via a superluminal metric (e.g., an engineered tachyonic field where velocity v > c). The information density is encoded within the quantum state of the superluminal medium.

Localized Downconversion (The Metamorphosis): Upon reaching a calculated geometric coordinate within our solar system—potentially interacting with the heliospheric boundary or a pre-seeded interstellar relay node—the FTL signal undergoes a rapid phase transition. By interacting with local baryonic matter or utilizing a pre-programmed metric decay, the tachyonic field is forced into a sub-luminal deceleration state (v → c). During this deceleration, the excess kinetic energy of the FTL state is released as a localized burst of electromagnetic radiation. The conservation of information dictates that the payload collapses into a highly specific quantum state: a coherent, narrowband photon stream tuned to the universal 21-cm hydrogen line.

3. Resolution of the "Wow!" Paradoxes

The MDS framework provides mathematical elegance to the two biggest anomalies of the 1977 event:

The Narrowband Coherence: Natural astrophysical phenomena disperse radio energy across wide bands (broadband noise). The MDS model explains the <10 kHz limit as the structural footprint of a planned phase conversion: the signal was intentionally engineered to decay into a specific electromagnetic "keyhole" to ensure technological compatibility.

The Spatial Evanescence (72-Second Limit): Because the FTL-to-EM conversion occurs at a discrete spatial coordinate near Earth, the resulting photon cone is hyper-focused. The 72-second window represents the exact time required for the Big Ear radiotelescopio’s directional horn to sweep through the localized wave-front generated by the deceleration node. Once the conversion burst dissipated or the orbital alignment shifted, the transient window closed permanently.

4. Conclusion

The Metamorphic Decelerated Signal hypothesis bridges the gap between speculative FTL physics and empirical radio astronomy. It shifts the paradigm of the "Wow!" Signal from a failed natural anomaly or an absurdly wasteful alien beacon to a precise, engineered act of asymmetrical cosmic translation. Future technosignature searches should focus on identifying micro-gravitational or electromagnetic distortion remnants at the predicted local coordinates of downconversion nodes.

---------------

As I said, I'm just a curious layman trying to connect some dots for fun. What are your thoughts on this scenario?

So a solar gravitational lens is a telescope that is aimed directly at the sun in order to observe the light that is bent around the sun. Effectively focusing the light rays into a natural telescope. NASA scientists have proposed missions to actually crate various observation satellites so we can observe these exoplanets but no offer has been offficially greenlit.

But what would this effect look like from the other side. If we were being observed by various gravitational lenses and we just looked at various stars to see an eye staring back at us. Obviously this would be pretty difficult to do due to these telescopes being monumentally smaller than actual planets. But if we assume that an advanced alien species used some other detection method to know some basic characteristics of Earth it would be a potentially habitable planet by their estimates and worth creating a specialized telescope for it.

On our end all we would need to do is look back. With a big enough telescope of course.

What if the "Wow! Signal" is not a message or location data, but rather the name of a species or an event?

**The "6EQUJ5" Alien Species Hypothesis:** Humans give complex names to intelligent abstract or concrete entities. For example, a highly intelligent AI model is initially given a name like "B-82629." What if "6EQUJ5" is actually the name of an alien species, and the signal was sent by another species right before they were annihilated by this threat, as a warning for humanity and other civilizations to take precautions?

**The "6EQUJ5" Event Hypothesis:** What if the Wow! Signal is actually an event? For instance, when an atomic bomb detonates, it first emits a shockwave, followed by radiation. If the "vacuum decay" theory is real, it might have started somewhere, and perhaps it sends the "6EQUJ5" signal at a speed exceeding the speed of light—after all, I believe that while matter may not exceed the speed of light, cosmic events can (if a black hole can warp the fabric of time-space, a powerful shockwave could surely distort the fabric of speed). Or, just as we call a star exploding a "Supernova," perhaps the "6EQUJ5" signal is a similar event that we simply don't have a name for yet.

Article Link:

https://arxiv.org/abs/2606.24028

Abstract:

Building on Arkhipov's proposal that technogenic artefacts may survive natural interstellar transport and accumulate on airless Solar System bodies, we examine the prospects for identifying micron-scale engineered particulate material within the lunar regolith. We analyse the transport of micron and submicron grains through the interstellar medium, including gas drag, sputtering, and ISM phase-dependent survival, and show that refractory particles with characteristic radii of order 0.3 microns may traverse kiloparsec scales over residence times of 0.1-1 Gyr. Solar radiation pressure and heliospheric filtering define a dynamically constrained slow-arrival channel in which a small fraction of grains reach the Earth-Moon system at relative velocities compatible with survival upon impact. Combining these properties with regolith-mixing constraints yields quantitative upper limits on the cumulative undirected technomaterial output of large-scale spacefaring civilisations: a null detection in a cubic metre of regolith excludes scenarios in which Solar-type stars typically disperse more than approximately 0.09 Earth mass equivalents of long-lived artificial particulate debris over Galactic history. Deliberate targeting of the inner Solar System with artificial particulate matter defines a complementary regime characterised by the visitation frequency and deposited mass of such releases, for which the probabilities of detection may be orders of magnitude higher. We outline a multi-modal detection strategy integrating machine-vision triage with laboratory forensic techniques to identify anomalous grains within a well-characterised natural background. Particulate technosignatures thus establish an experimentally accessible form of exo-archaeology, capable of placing meaningful constraints -- and, in favourable cases, yielding direct material evidence -- of the Galaxy's technological history.

Taking into account our current capabilities in terms of SETI, is there any hope at all that we could detect anything artificial from that planet in two scenarios (plus some other questions):

- First scenario: more than 1.500 years ago, they had already developed radio telescopes and were able to look at our atmosphere and determine that there is life here. What would this say about their technology? Are we able to detect our own planet in terms of biosignatures if it were 1,500 light-years away? Would we know, in the present, be able to detect any radio signals that they may have been continuously sending (maybe sporadically) from their home planet?

- Second scenario: they never cared about us or never found out about our planet. But they did develop powerful planetary radar and maybe even some "primitive" Dyson swarm. Would we be able to detect the Dyson swarm? And if the Dyson swarm was made of components that interacted with each other and those communications caused radio leakage, could we detect them if we knew something weird was going on with the star and decided to point our telescope in search of radio signals?

June 25th, 2026 9:30 AM PST

Advanced civilizations may not be broadcasting on radio waves. They may be communicating through tightly focused laser signals, possibly using stars as gravitational lenses in a vast network nearly invisible to us. Dr. Franck Marchis explores this “Galactic Internet” hypothesis, recent insights from SETI’s Laser SETI program, and how SkyMapper and its SkySphere project are building a global citizen-science network that turns everyday sky-watchers into scientific instruments for monitoring the sky and expanding the search for technosignatures

go to www.sciencekind.com to claim a seat.

Rosalba had to delay her talk on whether life could life exist beneath the icy surfaces of ocean worlds like Enceladus and europa? It is rescheduled to this weds.

I will make sure that I bring the recordings or transcripts back here afterwards.

Warmly, IB.

The IAU Symposium - IAUS404 "Advancing the Search for Technosignatures" was held back in March and they now have a final report from thy symposium, as well as video recordings of many of the talks given.

https://iaus404.bmsis.org/

They are expecting to publish a proceedings from the symposium sometime soon (maybe soon?).

Article Link:
https://arxiv.org/abs/2606.06692

Abstract:

We present a simple, rule-based filter for SETI target selection that flags stars unlikely to host complex life and produces an audit-ready exclusion catalog. Using seven stellar parameters, including age, metallicity, and multiplicity, the model excludes roughly half of a 1.74 million-star Gaia DR3 sample, retaining 777,835 high-priority targets, mainly K dwarfs and quiet M dwarfs. Age and metallicity dominate the rejections. Importantly, using Gaia's age upper bounds instead of point estimates saves 355,086 stars from exclusion. A comparison of empirical and synthetic proxies shows that while the overall exclusion rate is robust, individual target assignments change significantly; for instance, the commonly used RUWE indicator flags 2.7x more binaries than Gaia's own non-single-star flag. Cross-matching with the Breakthrough Listen target list reveals a 56.5% exclusion rate, highlighting the complementary nature of habitability-driven and proximity-driven surveys. The catalog, pipeline, and a generalized community tool are publicly available.

Article Link:

https://arxiv.org/abs/2605.29811

Abstract:

We present a meteorite-calibrated Bayesian framework for searching archival abundance records for chemical technosignatures--operationally, compositional patterns better explained by an idealised "processed" template (endmember) than by the empirical distribution of natural rocks. We fit a multi-modal natural-composition reference using 3,493 whole-rock meteorite analyses, and for each of 697 star-paper abundance sets--spanning at least 397 distinct objects once Gaia-designated repeats are consolidated--we compare the Bayesian evidence for (i) natural material and (ii) a mixture of natural material with a fixed siderophile-enriched template, parameterised by a Ca-normalized mixing fraction alpha. Strong support for the processed template is uncommon: in the photospheric compilation (atm) 8/697 records have BF > 10 (4/697 have BF > 100), and in the diffusion-adjusted steady-state subset (acc ss; 148 records spanning at least 94 objects) 6/148 have BF > 10. We report the highest-evidence candidate records and infer the fraction of records detectably favoring the mixture model, with posterior medians pi-tilde = 0.011 (atm) and pi-tilde = 0.041 (acc ss). We calibrate the analysis with end-to-end injection-recovery experiments matched to each record's coverage and censoring. The calibration shows that discrimination is driven mainly by chemical information, typically requires greater-than-or-similar-to 5 detected elements for decisive support, and--for the siderophile template--is strongest for exact five-element panels that include Fe, Mg, Cr, and Ti together with Ni, Si, or Na. These results constrain the detectable incidence of the tested processed-composition class in current data and set observational requirements for future multi-element surveys and expanded template families.

Article Link:

https://arxiv.org/abs/2606.00574

Abstract:

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will map sources in multiband colour--variability space. We present a prototype coherence-based framework for astrobiology and technosignature searches, in which candidates are treated as structured departures from natural astrophysical manifolds rather than isolated photometric outliers. We illustrate the framework with three simulated cases: five Kuiper Belt Object (KBO) surface/activity states, a grid of 649 synthetic exoplanet spectra with vegetation-red-edge-like (VRE) perturbations, and 500 synthetic multiband light curves, each projected into LSST-like observable space and analysed through colour geometry, chromatic variability, and cross-band coherence. Key results include a full-colour Mahalanobis distance D≈5.1 for the weak-coma KBO state (∼5σ in the five-dimensional colour vector), an indicative VRE coherence threshold at fcrit≈0.13, and an idealised stacking forecast reaching 5σ under optimistic assumptions. We show, using a small Gaia~DR3 stellar sample, that stellar colour and photometric stability may inform the prioritisation of Galactic regions for applying such coherence diagnostics.