Another aspect of the myth of Boann is that she bore Oenghus. She and the leader of the Tuatha De Danaan, the Dagdha, engaged in an illicit affair that resulted in the birth of this god of love. However, since both Boann and the Dagdha wished to keep their rendezvous a secret, they used their divine powers to cause the nine month gestation period to last but a single day - or so it seemed, for the sun was frozen in the sky for those nine months, never setting and never rising. On this magical day, Oenghus emerged into the world.
Do you have a specific question about Celtic mythology? Then try the Mythography forum!
Dictionary of Celtic Mythology
This book is a great source for information about Celtic mythology! Described as both a "who's who" and a "what's what", this reference book features entries on the important gods, heroes, and other characters from Celtic myth and legend. And there is a good entry on the goddess Boann.
If you want more recommended resources for information about Celtic myths, visit the books section - it lists books about mythology, art, literature, and more.