observerly’s lightweight, zero-dependency, fully-tree shakeable type-safe astrometry library for TypeScript. Accurately determine the positions of the Sun, Moon, and planets, handle coordinate transformations with ease, calculate transit times for any celestial object and integrate precision astronomy into your projects.
Python astronomy with bundled DE442-derived data (~0.001 arcsec typical OPM2 reconstruction difference from source). Powered by Taiyin C++: planets, stars, eclipses, events, Chinese calendars and astrology; optional BaZi and Ziwei Doushu packages.