I'm reading a book about the Anglo-Saxons, and the author wrote this:
The piece also shows us a superstition-ridden people, always ready to read meanings into famines and plagues and storms and comets and other phenomena that feature so regularly in the Chronicle.
The author is referring to records from 793 where the Vikings made their first impact on Anglo-Saxon England by sacking the monastery on Lindisfarne.
I was intrigued by the mention of comets. Did astronomical events have a significant impact on the Anglo-Saxon culture?
The book I've referenced is "The Anglo-Saxon World: An Anthology" by Kevin Crossley-Holland. The citation is on page 35.
I had a long answer typed up but the app crashed. I'll simplify for you.
Late 500s, Gregory de Tours did lots of empirical observation and wrote "The Course of the Stars", which accurately contains records of eclipses and Comets.
However,
The key source for this period is the Anglo Saxon Chronicle. It's a gold mine record for astronomy in the time period. Here's a source that will answer all questions you have:
http://adsabs.harvard.edu/full/1984JRASC..78L..56B
As an added bonus, Haley's comet showed up in 1066 and people at Hastings could allegedly see it.