 Astronomical Calculation Institute (Heidelberg University)

The Astronomical Calculation Institute (Astronomisches Rechen-Institut, or ARI) is a research institution associated with Heidelberg University in Germany. It focuses on various fields of astronomy and astrophysics, particularly those related to celestial mechanics, ephemerides, and astronomical calculations. The institute is known for its work on the mathematical modeling of celestial bodies, planetary motions, and the development of computational methods for astronomical data analysis.