Originally published October 2015.

Updated December 2019.

Irish Astronomers

Until the 1990’s it seems that a number of scholars thought that the Irish had lagged behind other European countries when it came to early observations about the heavens. However, Two Irish Scholars Daniel McCarthy an Aiden Breen have shown through a number of studies that the Medieval Irish actually studied the sky in systematic ways that were actually beyond the levels of observation in other parts of Europe.

The Irish used different and sometimes colorful terms for the phenomena they saw in the sky. Therefore, their observations were not previously recognized. MacCarthy and Breen were able to decode the terms and show that the “dragon” in the sky over Ireland in 735 was likely a very strong aurora borealis. The “red tower of flame” may have been a 1054 supernova, and that Haley’s Comet’s appearance in 1066 was the “hairy star” that they were describing.

They used contemporary accounts from other countries along with formulas connected to modern observations to make the correlations with the Irish descriptions. In 1054 an account from China described a “reddish white” star with “pointed rays that shone from all sides”. MacCarthy and Breen have shown that an explosion of a star in the Crab Nebula would have been visible in both China and Ireland at the time, and is the likely the phenomenon being described.

There were other observations make it clear that the Irish were doing more than just looking up and taking note of omens in the sky. They took note of less dramatic events as well. Breen and MacCarthy argue that observations made of lunar and solar eclipses in 688 and 691 suggest that people were deliberately watching the skies and not just seeing them by chance. One of the examples they provide was a description of:

“a thin and tremulous cloud in the shape of a rainbow appeared at the fourth vigil of the night on the sixth feria preceding Easter, from east to west through a clear sky.“

The authors argue that this showed they were also interested in the precise description of the event, and timing of the observation.

Obviously, the real reasons for these changes in the sky were not understood. They were often chronicled as possible omens of dire events. The super nova mentioned above actually coincided with the day of St. George, who in Irish tradition is the the slayer of the dragon of the antichrist. In spite of previous claims, it seems clear that early Irish scholars were making observations at least equal to those being made on the continent.