Technosignatures in existing data

Project Tarang

AI-based searches for technosignatures in public archival exoplanet datasets. The website documents ongoing progress and identifies future directions for mining existing Kepler, K2, TESS, and high-resolution spectroscopic archives to place observational constraints on the prevalence of technologically advanced extraterrestrial life.

Shadow search Megastructure-like occultation
Laser-line search Spectrum to repeatability to AI

Analysis progress

Tracking MegaMiner across the TESS sky.

With generous support from John Davie, we have developed an AI-enabled MegaMiner pipeline that is now searching millions of TESS threshold-crossing events (TCEs) for anomalous transit morphologies.

TESS survey coverage Full-sky sector projection
Sector 55 analyzed

Two search frontiers

A map of searchable technosignature observables in existing public exoplanet archives.

TechnoSurveys.com focuses on two technosignature classes that can be investigated with existing archival exoplanet data: anomalous photometric light curves and narrow laser-like spectral features. Both classes are tied to measurable observables, reproducible archive products, and follow-up tests that can separate astrophysical, instrumental, and artificial hypotheses.

01

Anomalous light curves

Search for asymmetric dips, evolving transit shapes, structured occultations, strange duty cycles, and quasi-periodic dimming in Kepler, K2, TESS, and ground-based photometry.

Enter the MegaMiner lab
02

Laser-like spectral features

Reuse high-resolution spectra as accidental laser-monitoring programs. The target is not a published radial velocity, but unresolved emission-like spikes in the underlying spectra.

Inspect spectral archives

The scale of the searchable archive

From accumulated observing time to testable megastructure populations.

Public photometric surveys already contain billions of effective star-hours. These two views connect that archive scale to the populations of 3%-dimming structures that can be investigated, using transparent survey-level assumptions and reproducible source tables.

Figure 1 · Archive growth

How much public photometric exposure has accumulated?

Cumulative effective integration, summed over every monitored star from 2009 through 2025.

Exposure by 2025 11.46 billion star-hours

Effective exposure counts actual photometric integration, not elapsed survey duration. Survey overlap is retained because the quantity is total available exposure rather than unique sky coverage.

Figure 2 · Illustrative occurrence reach

How rare a 3%-dimming megastructure population could each archive probe?

Captured stellar power is used as an engineering scale; lower curves indicate sensitivity to rarer populations.

Deepest modeled reach 1 in 47 million stars

The plotted quantity is a one-object reach metric, eta = 1/N in each 0.25-dex power bin. It is not a formal confidence interval or a catalog-derived population constraint.

Methods, assumptions, and limitations Open the reproducibility notes

Figure 1 derivation

Survey-level effective star-hours

Continuous space photometry uses the monitored-star count multiplied by annual wall-clock hours and a duty factor. Sparse ground surveys count only the summed exposure time of visits. Contributions are accumulated independently and then added by calendar year.

Eyear = Nstar × 8766 hr yr-1 × fduty Eyear = Nstar × Nvisit × tvisit
SurveyIntervalAdopted exposure prescription
Kepler prime2009-2013150,000 stars, 0.92 duty; partial-year factors of 0.58 in 2009 and 0.38 in 2013.
K22014-2018500,000 target light curves, 75 days each, 0.85 duty, distributed across the five observing years.
ASAS-SN2013-202550 million stars, 75 visits per year, 270 seconds per visit; 0.25 ramp factor in 2013.
TESS2018-202513 sectors per year, 27.4 days per sector, 0.90 duty; adopted target counts evolve from 15,000 to 10,000 per sector.
ZTF2018-2025500 million stellar sources, 50 visits per year, 30 seconds per visit; 0.75 ramp factor in 2018.

This is a conservative, literature-informed survey model rather than an exposure-ledger reconstruction. TESS full-frame-image light curves are excluded, and ASAS-SN and ZTF dominate the uncertainty.

Download Figure 1 source table

Figure 2 derivation

A phenomenological 3% captured-power scale

Each survey is represented by one million Monte Carlo stellar luminosities drawn from survey-specific Gaussian mixtures and scaled to the adopted archive population. Luminosities are converted to the power corresponding to 3% of the host star, then counted in 60 equal logarithmic bins from 1016 to 1031 W.

P3% = 0.03 Lstar etareach(P) = 1 / Nstar(P) K = [log10(P/W) - 6] / 10
Kepler/K2650,000 stars TESS1 million stars ASAS-SN50 million stars ZTF500 million stars

Bins with fewer than 10 expected stars are omitted. Kardashev Type I and II reference powers are marked at 1016 and 1026 W. A reach of 10-6 means approximately one million modeled stars occupy that power bin.

The luminosity distributions are synthetic, not catalog cross-matches. The 3% mapping does not specify geometry or collector area, and eta = 1/N is a reach metric. A zero-detection 95% upper limit would instead require approximately 3/[Nstar epsilon(P)], including injection-recovery completeness.

Download Figure 2 source table

Public datasets to mine

Public telescopes and archival instruments that define the TechnoSurveys search plan.

The initial search is built around public, data-rich facilities that already contain the relevant observables: precise time-series photometry and high-resolution stellar spectra.

Kepler space telescope against a star field
Credit: NASA
Space photometry

Kepler and K2

Long-baseline light curves make Kepler uniquely valuable for shadow imaging, long-term variability, missing transits, and structured dimming that evolves over many orbital cycles.

TESS spacecraft observing transiting exoplanets
Credit: MIT
All-sky photometry

TESS

All-sky monitoring of bright nearby stars supports searches for anomalous light curves, single odd transit events, asymmetric dips, and rare one-off occultations.

Keck Observatory telescope domes under the Milky Way
Credit: Keck Observatory
High-resolution spectra

Keck HIRES

Decades of high-resolution stellar spectra are well suited to narrow laser-like emission searches, repeatability checks, and nearby-star technosignature constraints.

La Silla Observatory under a starry sky
Credit: ESO
Precision radial-velocity spectra

ESO HARPS

Ultra-stable radial-velocity spectra can be re-mined for unresolved emission spikes, repeated narrow-line events, and spectral artifacts that survive telluric and instrumental vetoes.

Very Large Telescope unit telescopes with a laser guide star
Credit: ESO
Ultra-stable spectroscopy

VLT ESPRESSO

Exceptional resolving power and instrumental stability make ESPRESSO a priority archive for laser-line sensitivity estimates and rigorous false-positive rejection.

Flagship pipeline

MegaMiner searches folded TESS light curves for anomalous, repeated transit shapes.

MegaMiner is an AI-driven automated algorithm that uses ExoMiner as its main kernel, together with custom-built anomaly-detection tools, to identify sky-localized repeated transit events that exhibit unusual shapes.

MegaMiner on TARANG Compute node for large-scale TESS TCE analysis
Agentic-AI orchestration Coordinates scoring, anomaly filters, literature checks, and DV-report review
Original sample TESS TCEs

Approximately 1 million threshold crossing events from folded TESS light curves.

1 Ingest

TESS TCEs, quality masks, sector stitching, and catalogue matching.

2 Describe

Planet, astrophysical false-positive, and instrumental-artifact scores, plus ExoMiner-derived anomaly Z-scores for odd transit shapes.

3 Triage

A specially designed conditional autoencoder removes eclipsing binaries and other recurrent astrophysical contaminants.

4 Escalate

LLM-based searches of existing literature and catalogues, followed by LLM-assisted vetting of the TESS DV report.

TESS spacecraft observing transiting exoplanets
TESS public archive input
Science output

A ranked list of sky-localized, repeated, shape-anomalous transit events with archive provenance, ExoMiner context, autoencoder anomaly filtering, literature status, and DV-report evidence ready for human review.

Spectral mining map

High-resolution RV archives as accidental laser-monitoring surveys of nearby stars.

The search does not stop at published velocities. It asks whether the original high-resolution spectra contain narrow, emission-like features that survive checks against stellar physics, tellurics, cosmic rays, sky lines, and instrument behavior.

Continuum-normalized spectrum Synthetic demo
Stellar and telluric structure Candidate narrow feature Rejected mask region