Possible stellar asterisms carved on a protohistoric stone

Chisel marks on a stone uncovered in Rupinpiccolo protohistoric hill fort from north-eastern Italy were suggested to be a representation of the night sky (Bernardini et al. 2022 Documenta Praehistorica XLIX). The patterns of the 29 marks are analyzed here to establish if they reproduce popular stellar asterisms. Nine marks are found to match the Tail of Scorpius and five the Orion's Belt, together with Rigel and Betelgeuse. Nine marks are found in the approximate position of the Pleiades showing some match with the cluster members. On the back side, 5 marks possibly reproduce Cassiopeia. One mark slightly North of Orion cannot be identified. The 28 marks show a Pearson correlation coefficient r(28) with stellar positions higher than 0.99 with a probability p of a wrong correlation lower than 0.001. Departures are about one degree, or about 7 mm, as the mean diameter of the marks, which suggests a manufacturing limitation in the charting. The fort dates approximate to 1800-400 BCE when Scorpius and Orion showed about the same orientation at the heliacal rising. The unidentified mark challenges the whole picture. We suggest it could have been the progenitor of a failed supernova, thus offering also the possibility of a verification.

Automated summary

Chisel marks found on a stone in the Rupinpiccolo hill fort in northeastern Italy are suggested to represent the night sky. Analysis shows that some of these marks correspond to popular stellar asterisms, indicating intentional representation. The high correlation between these marks and stellar positions suggests ancient observations and recording of constellations. However, the identity of one mark remains unknown.