DOI: 10.5281/zenodo.17692904
title: 3I/ATLAS Photometric–Chromatic Anomaly (2025) 3I/ATLAS
title: Δv Geometry, Interstellar Anomaly Index, and Extended Post-Perihelion Evolution

description: 3I/ATLAS (C/2025 N1): Photometric–Chromatic Anomaly Analysis, Interstellar Anomaly Index, Δv-Based Dynamical Assessment, and Extended Post-Perihelion Evolution (Version 2.5)

This archive contains the complete v2.5 research dataset, analysis scripts, figures, LaTeX source, and cryptographic authenticity proofs associated with the study of the interstellar object 3I/ATLAS (C/2025 N1).Version 2.5 represents the most detailed and reproducible photometric, chromatic, dynamical, and anomaly-index analysis available to date.

The dataset incorporates:

🔭 Photometric & Chromatic Diagnostics





MPC photometry (May–Nov 2025)




Multi-filter colour indices (g–o, g–r, r–o)




Solar-referenced colour deltas




Optical acceleration time series with pre- and post-perihelion spikes




Post-perihelion fading extension to 2025-11-21



📈 New Dynamical Analysis (Δv Scaling & Jupiter Encounter Geometry)

Version 2.5 introduces a quantitative dynamical test of the optical-acceleration anomaly, converting the measured proxy into two calibrated non-gravitational impulses:





8 m/s minimal Δv — the value required to reproduce the~1×10⁵ km lateral offset invoked in Loeb’s Jupiter near–Hill-radius geometry




25 m/s photometric-inferred Δv — consistent with the fitted A₁ parameter



Both scalings show that two short-lived activity spikes (10 Sept and 2 Oct 2025) account for >90% of the total impulse.The Δv is sufficient to produce the course deviation required for Loeb’s scenario, whether interpreted as natural activity or a non-standard process.

📊 Interstellar Anomaly Index (IAI)

Version 2.5 formalises the Interstellar Anomaly Index, a four-component metric measuring:





Photometric anomaly




Chromatic anomaly




Dynamical anomaly




Morphological anomaly



3I/ATLAS obtains IAI ≈ 0.95, placing it at the extreme end of known interstellar visitors and distinctly separated from JFCs, LPCs, and 1I/ʻOumuamua / 2I/Borisov in (e, IAI) space.

📘 Manuscript

The full LaTeX source and compiled PDF of“3I/ATLAS (C/2025 N1): Photometric–Chromatic Anomaly, Δv Geometry, and Interstellar Anomaly Index”are included.

🔐 Cryptographic Proofs

All analysis files, scripts, and outputs are authenticated via:





SHA-256 digests




GPG signatures




OpenTimestamps proofs anchored on the Bitcoin blockchain




A reproducible “protect & seal” pipeline



Ensuring full forensic reproducibility of the analysis chain.
description: Version 2.5 – Interstellar Anomaly Index, Δv-Based Dynamical Assessment, and Extended Post-Perihelion Evolution

This release updates the 3I/ATLAS dataset with MPC photometry through 2025-11-21 (4,580 observations), providing a complete view of the object's pre- and post-perihelion behaviour. Version 2.5 integrates new dynamical modelling, refined anomaly quantification, extended colour and acceleration diagnostics, updated post-perihelion behaviour, and full cryptographic sealing for reproducibility.

Major updates in v2.5:





Δv-based dynamical analysis using the optical–acceleration proxy→ Two calibrated impulse regimes introduced:• 8 m/s minimal Δv (required for Loeb’s Jupiter near–Hill-radius geometry)• 25 m/s photometric Δv (consistent with the fitted A₁ parameter)




New dynamical figures• Δv time-series (impulse contribution per epoch)• Dual cumulative Δv comparison (8 m/s vs 25 m/s)• Overlay figure with identical temporal structure and scaled amplitude




Interstellar Anomaly Index (IAI) finalised• 4-component anomaly metric (photometric, chromatic, dynamical, morphological)• 3I/ATLAS obtains IAI ≈ 0.95, placing it at the extreme anomalous end among interstellar objects• Includes IAI–eccentricity diagram and anomaly-component radar plot




Extended post-perihelion evolution• Photometry expanded to 2025-11-21• Smooth, monotonic fading• Stable negative acceleration• No secondary activation or fragmentation detected




Updated manuscript & figures• Revised LaTeX paper with new sections on Δv geometry and the IAI• Extended anomaly tables• Updated plots for colour evolution, optical acceleration, and post-perihelion behaviour




Complete reproducibility chain• SHA-256 digests, GPG signatures, and OpenTimestamps proofs• All scripts included for end-to-end re-execution• Proof bundles with forensic-grade temporal traceability




Expanded Python analysis suite• atlas_delta_v_from_optical_proxy.py• atlas_optical_dv_dual.py• plot_atlas_optical_accel_deltav.py• (plus the full colour, acceleration, and IAI pipelines)





This version supersedes v2.4 and provides the most complete, timestamp-verified, photometric–chromatic–dynamical record of the 3I/ATLAS 2025 apparition, establishing the current reference dataset for interstellar anomaly studies.
description: 1. 🧩 Files Included (v2.5)








Category
Description




I3_ATLAS_v2_5_Analysis.pdf
Main analytical report containing all figures, tables, Δv-analysis, chromatic evolution, IAI summary, and post-perihelion behaviour.


data/
Cleaned and calibrated photometric time-series, including: • I3.txt (raw MPC photometry) • I3_Optical_Acceleration_Data.csv • I3_Color_Alerts_*.csv • Colour statistics and derived time-series CSVs


figures/
All plots generated in v2.5, including: optical acceleration, colour–acceleration correlation, Δv impulse curves, Δv overlays, IAI diagrams, and post-perihelion evolution.


scripts/
Complete Python analysis suite: colour-index extraction, optical acceleration, Δv modelling, IAI computation, and all figure-generation routines. Fully reproducible.


proof_bundle/
Cryptographic verification artifacts: SHA-256 manifests (.sha256), GPG signatures (.asc), and OpenTimestamps proofs (.ots), ensuring forensic-grade provenance.






 
description: 🧠 Scientific Context

This release confirms that photometric diagnostics alone can provide early detection of dynamical anomalies in interstellar objects—well before astrometric orbit fits reveal acceleration.The optical–acceleration proxy developed here captures:





The timing of activity bursts,




The spectral (colour) evolution linked to those bursts,




The buildup of integrated non-gravitational Δv,




And the transition from activation to post-perihelion fading.



Because the proxy uses inverse magnitudes and time-derivative structure, it is instrument-independent, cost-effective, and immediately applicable to future interstellar visitors. It complements orbital-dynamical methods by revealing acceleration precursors in the photometry.

In v2.5, this method is extended to a Δv-based dynamical assessment, demonstrating that the observed impulse is dynamically capable of producing the small course adjustments associated with the proposed Jupiter near–Hill-radius geometry.

This establishes photometric anomaly analysis as a legitimate, reproducible, and early-warning tool for interstellar object characterization.
description: 🔐 Verification and Reproducibility

All analytical assets are timestamped, hashed, and digitally signed.The protect_atlas_v2_5.sh script generates a deterministic proof bundle containing:





SHA-256 integrity manifest




GPG signature (.asc)




OpenTimestamps blockchain proof (.ots)



These provide verifiable provenance and cryptographic reproducibility for all datasets, figures, and analysis scripts.

Check folder manifests with the files:




Manifest File
Purpose




manifest_v2_5.txt
The document itself


manifest_v2_5.txt.sha256
Integrity/authenticity hash


manifest_v2_5.txt.asc
GPG signature: proves authorship


manifest_v2_5.txt.ots
Bitcoin timestamp: proves date
description: 📚 Suggested Citation



Gherbi, Salah-Eddin (2025).3I/ATLAS (C/2025 N1) — Photometric–Chromatic Anomaly Analysis, Interstellar Anomaly Index, Δv-Based Dynamical Assessment, and Extended Post-Perihelion Evolution (v2.5).Zenodo. https://doi.org/10.5281/zenodo.17692904
description: 🪶 Project Metadata

Project: 3I/ATLAS Photometric–Chromatic Anomaly SeriesScope: Independent research programme (2025 – ongoing) focused on photometric, chromatic, and dynamical diagnostics of the interstellar object 3I/ATLAS (C/2025 N1).

Author: Salah-Eddin GherbiIndependent researcher — photometry, interstellar object analysis, planetary dynamics, anomaly quantification.

Reproducibility Pipeline:protect_atlas_v2_5.sh — automated archival and authentication pipeline using:





SHA-256 manifests




GPG detached signatures




OpenTimestamps (Bitcoin-anchored) proofsensuring full temporal integrity and verifiable provenance of the dataset.



Previous Release:v2.4 — Established empirical baselines, colour-index pipeline, and reproducibility infrastructure.

Current Release:v2.5 — Δv-based dynamical modelling, Interstellar Anomaly Index (IAI), extended post-perihelion evolution, updated manuscript, complete pipeline and proof bundle.

License: CC BY-NC-SA 4.0Open for non-commercial use with attribution; derivatives permitted under identical terms.