Early Irish astrology is the obscure astrological system practiced by the ancient Irish. Little is known about this native system of astrology, as it is only described in a few Old Irish manuscripts, none of which have been published or fully translated.
Using early Irish sources, Ellis attempted to reconstruct an earlier Celtic calendar, arguing that "a study of linguistic concepts and early cosmological motifs and calendrical philosophies of both Celtic (inclusive of Old Irish) and Sanskrit/Vedic cultures give a path back to the common Indo-European roots of our cultures".
Additional References 
- Maxwell II. Close, 'Remarks on a Cosmographical Tractate in the Irish Language', Proceedings of the Royal Irish Academy, Vol vi, 1900–1902, p. 457-460.
- Henry S. Crawford, 'Notes on the Irish Zodiac Preserved in the Library of Basel', Journal of the Royal Society of Antiquaries of Ireland, vol iv, 1925
- Mario Esposito, 'On the pseudo Augustinian treatise De Mirabilius & etc.', Proceedings of the Royal Irish Academy, Vol xxxv, 1918–20.
- D. McCarthy and Dáibhi Ó Cróinin, 'The "Los"' Irish 84 year Easter Table rediscovered', Peritia, 6–7, 1987/8
- D. McCarthy, 'The Chronological Apparatus of the Annals of Ulster AD 431-I 131', Peritia, 8(1994)
- Dáibhi Ó Cróinin, 'Mo-Sinu maccu Min and the computus at Bangor', Peritia, 1982
- Dáibhi Ó Cróinin, 'A Seventh Century Computus from the Circle of Cummianus', Proceedings of the Royal Irish Academy, vol. lxxxii (1982)
- Maura Power, An Irish Astronomical Tract, based on a Medieval Latin version of a work by Messahalah, Irish Text Society, London, 1914.
- William Reeves, 'On Augustin, an Irish writer of the 7th Century', Proceedings of the Royal Irish Academy, Vol ii, 1861
See also