Astrometric Accuracy of Positions

TL;DR

This paper reviews the historical progress and recent advancements in astrometric accuracy, highlighting new diagrams, Gaia DR3 data, and contributions from past astronomers to illustrate the field's development.

Contribution

It introduces two new diagrams showing astrometric accuracy over time, incorporating recent Gaia data and historical insights, offering a comprehensive overview of progress.

Findings

New diagrams illustrate accuracy improvements over time.

Inclusion of Gaia DR3 data enhances current understanding.

Historical contributions provide context for modern advancements.

Abstract

The great development of astrometric accuracy since the observations by the Greek astronomer Hipparchus about 150 BC has often been displayed in diagrams showing the accuracy versus time. Two new diagrams are provided here, one for positions only, another including parallaxes. New information is included on the Gaia DR3 data and the coming data releases, and about two great astronomers from the distant past, Wilhelm in Kassel and al-Sufi in Isfahan.