Precise dating of the Ptolemaic constellations

Determine the precise establishment ages of the 48 constellations attributed to Claudius Ptolemy in the Almagest star catalogue, beyond the current constraint that they existed by approximately 150 CE, and ascertain whether claims of substantially older origins (including proposals of tens of thousands of years) are supported by evidence.

Background

The study analyzes the creativity of astronomers via constellation complexity across the 88 IAU-designated constellations. The oldest set comprises the 48 constellations included in Ptolemy’s Almagest, which ensures they were established by around 150 CE.

The authors explicitly acknowledge that the precise ages of these constellations are unknown. While they likely predate 150 CE, the exact dating is disputed, with some claims suggesting extremely ancient origins. Establishing precise ages would clarify the historical timeline underlying the paper’s temporal grouping and address contested assertions about antiquity.

References

For the 48 Ptolemaic constellations we do not know precise ages but their appearance in the star catalogue included in the Algamest by \citet{Ptolemy} gives them a definite constraint of having been established by around the year 150 --- though they are all likely much older, and some contentious claims put some of these constellations at dating back tens of thousands of years \citep{BBC2000, Sparavigna2008, Faris2018}.

— Astronomers Getting Less Creative Over Time Is Why This Title Isn't Better (2503.23614 - Lund, 30 Mar 2025) in Subsection Data (Section Methods)