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Ephemeris Wiki

A .NET 10 astronomical ephemeris library — compute positions of the Sun, Moon, planets, asteroids, and stars from any observer location on Earth. Includes astrological house systems. Powers the Ephemeris Research App, a celestial visualization and simulation platform for Biblical cosmology researchers.

Research App

✅ Fully implemented — 8 PRs merged, build passing, 420/420 tests green (2026-03-22).

Documentation for the Ephemeris Research App — the celestial visualization and simulation platform built on this library.

Page	Contents
Research-App	User persona, UX principles, user flows, scriptural use cases (Hezekiah's Sundial, Joshua's Long Day), screen specs, simulation requirements, and feature roadmap
Wireframes	Screen-by-screen clickable wireframes for all 5 app screens

Documentation

Algorithm Reference

Page	Contents
Algorithm-Reference	All algorithms, formulae, and source references (Meeus chapters, IAU standards) — timekeeping, solar, lunar, lunar libration, planetary, asteroid ephemeris, astrological houses, nutation, precession, rise/set, eclipses, stellar, SPICE

Reference Format Specifications

These documents describe the binary and text file formats supported by the Ephemeris.Import namespace.

Page	Contents
SPK-BSP-Format	NAIF DAF/SPK binary ephemeris format — file records, summary records, segment descriptors, Type 2/3 Chebyshev layout
SE1-Ephemeris-Format	Swiss Ephemeris SE1 binary format — Chebyshev polynomial segments, body metadata, coordinate pipeline
SEFStars-Catalog-Format	Fixed star catalog text format (sefstars.txt) — column definitions, proper-motion & parallax corrections
Yale-BSC5-Format	Yale Bright Star Catalog 5th edition — fixed-width ASCII record layout, field definitions

Project READMEs

Each project in the solution has its own README with setup instructions, key classes, and wiki links.

Project	README	Description
Ephemeris	README	Core library — namespace map, public API, coordinate conventions, DI
Ephemeris.Tests	README	TUnit test suite — how to run, test categories, snapshot and mock patterns
Ephemeris.Benchmarks	README	BenchmarkDotNet — how to run, benchmark classes, result interpretation
Ephemeris.UI	README	WinForms app — forms, MVVM pattern, ScottPlot/OpenTK/SkiaSharp
Ephemeris.UI.Avalonia	README	Cross-platform Avalonia research app — OpenGL sky view, ScottPlot altitude chart

Project Links

• Source code
• NuGet package
• Issue tracker