Christmas storybook; How The Hibernators Came to Bethlehem, by Norma Farber, illustrated by Barbara Cooney. New York: Walker & Co. $6.95

This slim book adds a charming new dimension to the Christmas story. Its tale is pure and simple: The star of Bethlehem lovingly draws even winter's hardiest sleepers -- the hibernating animals -- to the manger at the inn.

As the star shines on from page to page, the reader receives a lesson in nature as well. Colorful illustrations give close-ups of all sorts of winter animals awakening in their varied dens and nests. The habits of each hibernator are further explained by the text.

It's difficult to suggest an age group for this beautifully illustrated story. The layout of textual blocks on pages full of large, sweeping pictures would delight five- or six-year-olds. But the poetic style of the story has too many challenging similes and artistic touches for that age group to appreciate and seems more appropriate for readers 9 and up.