# Constraining Delta-T from Babylonian Lunar Appulse and Occultation Observations

## TL;DR

This paper analyzes 15 ancient Babylonian lunar observations to refine estimates of Earth's clock error, $$T, and proposes a revised quadratic model based on these findings.

## Contribution

It provides new constraints on $$T using detailed analysis of Babylonian lunar observations, improving existing models of Earth's clock error history.

## Key findings

- Results align with previous $$T reconstructions from solar eclipses.
- Suggests a revised quadratic fit for $$T based on new data.
- Enhances understanding of Earth's clock error over 500 years.

## Abstract

We examine in detail 15 Babylonian observations of lunar appulses and occultations made between 80 and 419 BC for the purpose of setting useful limits on Earth's clock error, as quantified by $\Delta$T, the difference between Terrestrial Time and Universal time. Our results are generally in agreement with reconstructions of $\Delta$T using untimed solar eclipse observations from the same period. We suggest a revised version of the simple quadratic fit to $\Delta$T in light of the new results.