old Irish zodiac was obviously heavily influenced by Greco-Latin
ideals, and translated straight into Irish, although it is interesting
that Leo is called 'Cú', The Hound, and not Leon, the Lion.
There is some evidence to suggest constellation groupings like the
were perceived in ancient Ireland. Other constellations which were
recognised as groupings include Orion (which was known in various
forms, most notably Nuadu of the Silver Hand) and Cassiopeia
and the Northern Crown. Cygnus, The
Swan, was probably recognised as a constellation too. The Milky
Way was known as 'The Way of the White Cow, and has led Mythical
Ireland to believe the ancient 'river goddess' Boann (illuminated
cow) was in fact meant to be the Moon, and that Newgrange,
which is known in Irish as Brú na Bóinne, is not just
a construct designed to capture Winter Solstice sunrise, but also
Full Moon rise at certain times of the lunar cycle. Brú na
Bóinne could mean 'womb of the moon'.
Irish Astrology - An Historical Argument: Interesting article
by Peter Berresford Ellis. Note references to Milky Way, Bealach
na Bo Finne.