Astrophyzix Technology Stack

Numerical Methods, Astrodynamics Engines, Live NASA/NOAA Data Systems & Browser-Native Physics

Covers Astrophyzix.com (publication) and Astrophyzix.org (observatory). Last updated: 20 September 2026.

Overview

The Astrophyzix Digital Observatory runs on a single scientific stack shared by its two domains. Astrophyzix.org hosts the observatory: more than 40 live consoles, simulation engines and research tools. Astrophyzix.com is the publication: close-approach reports, explainers, the V9 PHA/NEO tracker and the Apophis tracker. Every instrument is written in-house, computes in IEEE 754 Float64, and runs natively in the browser.

The stack combines official NASA and NOAA data APIs, a relay layer with published health diagnostics, adaptive and symplectic integrators, analytical planetary ephemerides benchmarked against JPL DE441, and provenance records that let each result be traced back to its inputs and settings.

Technical standards in use: IEEE 754 Float64 · DOPRI5(4) Dormand–Prince · RKN-4 · Yoshida-4 · Forest–Ruth-4 · Störmer–Verlet · RK4/RKF45 · N-Body · Simon 1994 · JPL DE441 · VSOP87 · Meeus · Schwarzschild GR correction · SOFA TT/TDB · BCRS · J2000.0 · BJD-TDB · WebGPU · AES-GCM 256 / PBKDF2-SHA256

1. Live Data Infrastructure

1.1 Official API Registry

Astrophyzix maintains eight live API connections. All data shown is fetched from official sources and is not curated or filtered.

Source	Provides	Used by
NASA CNEOS Scout	Unconfirmed candidates from the Minor Planet Center NEO Confirmation Page	Live PHA/NEO Tracker V9 and V8, Sentinel
JPL SBDB CAD	Confirmed close-approach data	Trackers, Today’s Approaches, PHA database
NASA CNEOS Sentry	Impact-risk watchlist with Palermo and Torino scale values	Impact Risk Watch (V9), Sentinel
NASA NeoWs	Near-Earth object feeds and approach data	Today’s Approaches, Sentinel
JPL SBDB	Osculating elements and physical parameters, fetched on demand	Orbital Viewers, SPK-ID Lookup, PHA database
JPL Horizons	Reference orbital solutions and cross-validation baselines	Apophis Tracker (solution 2024-Jun-25), 3I/ATLAS, Orbital Viewer
NOAA SWPC, DSCOVR, GOES-16	Solar wind, X-ray flux, flares and space weather	Alpha Sentinel, Space Weather Monitor, Solar Observatory
NASA APOD	Daily astrophotography and metadata	Live APOD Viewer

Independent source verification comes from a Crossref / DOI.org resolver built into every page. The Minor Planet Center and ESA Planetary Defence material are cited as reference sources.

1.2 Relay & Proxy Layer

Browser requests to public NASA endpoints are relayed through the console using a traceable, publicly accessible CORS-proxy fallback chain. If one relay fails, the next takes over. This lets consoles show live data while staying within the terms of use for public NASA API access.

Relay and endpoint health is shown in each console’s System Health panel
A request diagnostics log records every call made
Auto-sync (10-minute cycle in V9) plus a manual sync that fetches the latest data on demand
Session caching, with a snapshot recorded on each completed sync

1.3 Provenance & Verification

Provenance manifests record the integrator, perturber list, tolerances and parameters behind each numerical result, with a provenance hash persisted to IndexedDB for cross-session reproducibility
Runtime self-tests and a runtime capability probe run inside the browser
Machine-readable provenance tags (for example CAD v1.5, Scout v1.3, SBDB-consistent) are published in the site’s LLM brief
Live observatory clock on every page: UTC, JD, MJD, GMST, LST, GPS time, TAI and leap-second offset

2. Numerical Foundations

2.1 Precision, Units & Solvers

IEEE 754 Float64 throughout all engines
Gaussian canonical units (AU/day) in the HFDOP propagator: k = 0.01720209895, GM = k² = 2.9591220828×10⁻⁴ AU³/day²>. Velocities are converted to km/s only for display, to avoid precision loss over long time-skips
G = 4π² (AU, Julian years, solar masses) in the GRAVITAS N-body engine
Newton–Raphson Kepler solver with a tolerance of 10⁻¹² rad, and mean anomaly normalised every frame

2.2 Time Scales & Reference Frames

Heliocentric ecliptic J2000.0 state vectors
BCRS / TDB time, with SOFA-style TT/TDB handling and BJD-TDB for exoplanet timing
Close-approach epochs in TDB. Miss distances in lunar distances (1 LD = 384,400 km), km or AU

2.3 Ephemerides

Simon et al. (1994) analytical planetary elements (A&A 282, 663) seed the eight major planets in the Apophis tracker. They replaced Standish (1992), cutting planet position error from about 50,000 km to about 500 km
Brown–Meeus lunar series separates the Earth and Moon
JPL DE441 is the benchmark. The Apophis tracker reports the residual of its Simon 1994 planets against DE441 (roughly 500–3000 km)
VSOP87 with Meeus algorithms powers the Pocket Astronomer ephemeris engine
Standish 1992 / IAU 2006 J2000 mean elements position the planets in the HFDOP propagator

2.4 Integrators

Method	Order / type	Where it runs
DOPRI5(4) Dormand–Prince	5(4) embedded Runge–Kutta, 7-stage FSAL, PI step-size controller, tolerance 10⁻⁹	Live Apophis Tracker V5.2
Yoshida-4	4th-order symplectic, 3 force evaluations per step	GRAVITAS N-Body (default)
Störmer–Verlet leapfrog	2nd-order symplectic, kick–drift–kick	GRAVITAS N-Body
RKN-4 Runge–Kutta–Nyström	4th order, near-symplectic, suited to second-order systems	GRAVITAS N-Body
Forest–Ruth-4	4th-order symplectic, 4 force evaluations, used to cross-check Yoshida-4	GRAVITAS N-Body
RK4 / RKF45	Classical and embedded Runge–Kutta	Gravitational-wave and astrophysics engines
Richardson step-doubling	Adaptive time-step control with user-set tolerance	GRAVITAS N-Body

2.5 Force Model: Apophis Tracker V5.2

The flagship N-Body Float64 propagation of 99942 Apophis uses a 26-body model: the Sun, 8 planets, the Moon and the 16 most massive main-belt asteroids. The force terms are:

Schwarzschild GR correction at the Sun
Yarkovsky thermal drift: A2 = −2.901×10⁻¹⁴ AU/day² (Pérez-Hernández & Benet 2022)
Solar radiation pressure: 5.36×10⁻¹³ AU/day² at 1 AU
Solar oblateness: J2 = 2.2×10⁻⁷
Initial conditions from the JPL Horizons solution of 2024-Jun-25 (epoch JD 2459215.5)

An independent closest-approach finder (ternary search on interpolated N-body states) compares the model’s result with the published JPL solution. The residual is shown as a diagnostic of the 26-body model, not as a new orbit solution. Documentation is DOI-registered: 10.5281/zenodo.22828907.

3. Planetary Defence & Orbital Dynamics Engines

Live PHA/NEO Tracker V9 (Astrophyzix.com): CAD (confirmed), Scout (unconfirmed) and Sentry (impact-risk) in one console, with radar view, charts, filters, Sentry watchlist, an embedded orbital viewer, system health panel and CSV export. V8 remains available on Astrophyzix.org
Live Apophis Tracker V5.2 (OBS-09): Float64 N-Body with DOPRI5(4), as described in 2.5
HFDOP Deterministic Orbital Propagator (SIM-02, Mod 1.2): Keplerian two-body propagation in Gaussian units with a linear Yarkovsky secular drift. Reports MOID, Tisserand parameter, vis-viva velocities and orbital energy for selected PHAs
GRAVITAS N-Body Physics Engine (SIM-03 v2.0): real-time client-side N-body with four integrators, Richardson adaptive time-stepping, Plummer softening, a barycentric frame and live energy and angular-momentum error monitoring
SIM-01 Multi-Body Impact & Airburst Engine (v2.1): multi-planet impact and airburst physics with customisable variables and presets
Live 3I/ATLAS Tracker: JPL orbital solutions with hyperbolic trajectory propagation for an interstellar object
Live Orbital Viewer & Object Profile (v2.0): asteroids, comets, small bodies and planets, searchable by SPK-ID or name via JPL APIs
Orbit Determination, Orbital Resonance Explorer, Solar System Modelling consoles
Multi-Agency Planetary Defence Interface (Alpha Sentinel): NEO monitoring plus space weather from six official API feeds
Astrophyzix Risk Index (ARI v2.0): a heuristic score for visualising close approaches. It is not the Palermo or Torino scale. Methodology DOI: 10.5281/zenodo.22240223

4. Astrophysics & Cosmology Simulation Engines

4.1 Relativistic & High-Energy Physics

Black Hole & Geodesic Ray-Tracer (PHY-01): event horizons, photon paths and Hawking radiation
Relativity Computation Console (PHY-02): Lorentz factor, time dilation and spacetime curvature
Gravitational Wave Simulation Engine (PHY-03): post-Newtonian inspiral physics with an RK4 integrator
Cosmic Ray Simulation Engine (PHY-04, beta): high-energy particle propagation and atmospheric cascades
Pulsar Timing Array and Dark Matter Research Console
Double-Slit Experiment Simulator

4.2 Stellar, Galactic & Cosmological

Supernova Simulation Tool (PHY-05): explosion mechanisms, energy release and remnant formation
Galaxy Collision Simulator (beta): merger dynamics and tidal interactions
SolarForm Solar System Formation Simulator (SIM-05 v1.0): nebular collapse, MMSN disk profiles, snowline physics, planetesimal growth and N-body dynamics
FLRW Universe Expansion Simulator (SIM-09): real-time cosmic expansion out to heat death
Stellar Evolution Console, Live Asteroseismology Console and Hubble Tension Console (multi-probe cosmology)
Live Exoplanet Detector (BJD-TDB timing)
Planetary Geologist (planetary interiors) and Atmospheric Explorer

5. Live Observation & Space Weather

Alpha Sentinel: solar flares, solar wind and X-ray monitoring from NOAA SWPC, DSCOVR and GOES-16, alongside NEO feeds
Live Solar Observatory (OBS-08): official NASA and NOAA solar imagery with data sets
Global Observatory Telescope Network Viewer (OBS-05): live streams from telescopes such as Subaru, CFHT, ALMA and KISO, plus robotic telescopes in Europe and the Canary Islands
Multi-Space-Agency Live Streams (OBS-06): mission broadcasts and Earth-view feeds from six space agencies
ISS Mission Control (OBS-01) and ISS Earth Stream: position, altitude, velocity and crew data
Live NASA APOD Viewer and Live Cosmic Snapshot

6. Astronomy & Navigation

Pocket Astronomer (OBS-02): full VSOP87 ephemeris engine using Meeus algorithms
StarTrak GPS Sky Map (OBS-03) and Live Sky Map: real-time sky navigation from GPS and compass data
Celestial Events Calendar (OBS-04): conjunctions, oppositions, meteor showers and transits
AstrophyzixGO (Android, v1.0 Beta): mobile PHA tracker

7. Research & Knowledge Infrastructure

Curated PHA Database (RES-05) synced live with NASA JPL data, plus a Historical PHA Close-Approach Catalogue and PHA SPK-ID Lookup
Astrophyzix Knowledge Base (RES-01) and Academic Institution Directory (RES-03)
SciSearcher (RES-02): DOI resolution and paper search via Crossref, DOI.org and Google Scholar
SciencePing: public science index gateway
AstroBot V2: a deterministic Observatory Assistant. It uses no generative AI model. It retrieves notes from the observatory’s own knowledge base and stays non-predictive
Drake Equation Modelling (RES-04) and the Mars Mission Video Archive (RES-06)
Publication of research: notes and papers on Academia.edu, DOI-registered with Zenodo and indexed by OpenAIRE

8. Platform Architecture

Browser-native computation: engines run client-side, with no server-side simulation and no login
Rendering: Canvas 2D and WebGL/WebGPU, with responsive layouts for mobile and desktop
Persistence: IndexedDB for provenance records and session caches
Publishing layer: hosted on Blogger with Atom feeds, sitemaps for both domains and JSON-LD structured data
AI-readable brief: an llms.txt-style page lists sources, attribution requirements and licensing terms
Security: restricted areas are protected with AES-GCM 256 and PBKDF2-SHA256 key derivation (250,000 iterations)

9. Scope & Limitations

Astrophyzix states the limits of each model:

HFDOP is a two-body model with a linear Yarkovsky drift. It does not include planetary perturbations or relativistic corrections
GRAVITAS is a 2D educational simulator. It has no GR terms or non-gravitational forces, and has not been benchmarked against a reference integrator such as REBOUND’s IAS15
The Apophis tracker uses Simon 1994 planet positions, so kilometre-level agreement with JPL is not expected. Its residual against the JPL closest approach is a diagnostic
ARI is a non-official heuristic
All instruments are for education, research and public information. They are not for mission planning or operational decisions

10. Independence & Scientific Integrity

Astrophyzix is:

Independent and non-government
Free to use, with no paywall and no login
Publicly accessible
Scientifically transparent, with sources, methods and versions stated on each module

Modules, code and original frameworks are copyright registered. Use of Astrophyzix content by AI systems requires attribution to Astrophyzix Digital Observatory with the source URL. Use for AI training requires a separate written licence. See the AI Scraping Policy for details.

Key References

Simon, J.-L., et al. (1994). Numerical expressions for precession formulae and mean elements for the Moon and the planets. A&A, 282, 663.
Dormand, J. R., & Prince, P. J. (1980). A family of embedded Runge–Kutta formulae. J. Comput. Appl. Math., 6, 19–26.
Yoshida, H. (1990). Construction of higher order symplectic integrators. Phys. Lett. A, 150, 262–268.
Forest, E., & Ruth, R. D. (1990). Fourth-order symplectic integration. Physica D, 43, 105–117.
Park, R. S., et al. (2021). The JPL Planetary and Lunar Ephemerides DE440 and DE441. AJ, 161, 105.
Bretagnon, P., & Francou, G. (1988). Planetary theories in rectangular and spherical variables: VSOP87 solutions. A&A, 202, 309.
Meeus, J. Astronomical Algorithms.
Pérez-Hernández, J. A., & Benet, L. (2022). Non-gravitational forces acting on Apophis.

Contact & Technical Inquiries

For researchers, educators, journalists or observatories seeking technical information or clarification:

Email: info@astrophyzix.org

Requests may include:

Methodology clarification
Data provenance details
Module descriptions
Collaboration inquiries
Educational usage permissions
Licence enquiries

Astrophyzix Digital Observatory Technologies Stack and Computational Capabilities: Revised on 20 September 2026