About AR00.space
AR00.space is a free, open-source astronomical calculator that brings professional-grade celestial computations to everyone — from amateur stargazers to astronomy students.
The Library
At its core, AstroCalc is a .NET computational astronomy library implementing classical algorithms from authoritative references in the field. Every calculation cites its source — you can trace each result back to the original formula.
Primary References
- • Jean Meeus — Astronomical Algorithms
- • Jean Meeus — Astronomical Formulae for Calculators
- • U.S. Naval Observatory — Almanac for Computers
- • W.M. Smart — Textbook on Spherical Astronomy
Technical Details
- • Written in C# 13 / .NET 10
- • 30+ calculation classes, 186 unit tests
- • Pure functions, immutable types, strongly typed
- • No external astronomy dependencies
What You Can Do
Sun
Sunrise, sunset, twilight, solar position
Sunrise, sunset, twilight, solar position
Moon
Phases, position, eclipses, features
Phases, position, eclipses, features
Planets
All 8 planets, Jovian moons, Saturn's rings
All 8 planets, Jovian moons, Saturn's rings
Deep Sky
110 Messier objects, bright & double stars
110 Messier objects, bright & double stars
Optics
Telescope & eyepiece calculations
Telescope & eyepiece calculations
Planner
Observing sessions, "what's up tonight?"
Observing sessions, "what's up tonight?"
Open Source
AstroCalc is released under the MIT License. The source code is available on GitHub.
View on GitHubBuilt with ❤️ for astronomy by Roberto Gramellini. This web application was built with the assistance of GitHub Copilot CLI.